German Climate Observing Systems

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Inventory report on the Global Climate Observing System (GCOS) Imprint

Editor and publisher Deutscher Wetterdienst, Frankfurter Straße 135, 63067 Offenbach a. M. www.dwd.de

Editorial team Stefan Rösner, Jörg Rapp, Klaus-Jürgen-Schreiber, Karsten Friedrich with the assistance of Grit Steiner and Gabriele Engel (co-ordination of translation). (Deutscher Wetterdienst, Offenbach a. M.)

Layout Karin Borgmann Grafikdesign (Offenbach a. M.)

Printed by Atelier Maiberger (Stockstadt a. M.)

Citation recommendation Deutscher Wetterdienst, 2013: German Climate Observing Systems. Inventory report on the Global Climate Observing System (GCOS). Self-published by DWD, Offenbach a. M., 130 pages.

Cover image DWD climate reference station at Hohenpeissenberg, Stefan Gilge/DWD

ISBN Print: 978-3-88148-462-6 Electronic: 978-3-88148-463-3 Note: This report was previously published in German language, ISBN 987-3-88148-460-2

Copyright All rights reserved. Any reproduction, even partial, is prohibited. No part of the publication may be reproduced in any form whatsoever whether by photocopy, microfilming or any other means, not even for teaching purposes, nor be processed or distributed by any electronic means without the written permission of the Deutscher Wetterdienst. Responsibility for the content of contributions lies with the authors.

Internet reference www.gcos.de

Last updated January 2013 German Climate Observing Systems

Inventory report on the Global Climate Observing System (GCOS)

Foreword

For considering necessary measures and their effects, political and economic decision-makers require a wealth of up-to-date and wide-ranging information. It is most important to have profound knowledge of the state of the climate system in the past, today and in the future. To further develop this know-how, research is similarly dependent on robust data and information. The provision of such information requires long-term, scientifically sound collection and storage of data. Continuous long-term observation of all climate system components and the scientific processing of the data gathered are indispensable to identify changes in the climate, deepen the understanding of the causes and warn in good time of any extreme events or sweeping impacts. Long, uninterrupted measurement series and observations alone make it possible to strive for such early identification of any change in the climate system and any related changes in the frequency and intensity of extreme weather events. The first steps towards worldwide observation of weather and climate Michael Odenwald, were made in Germany back in 1780 with the foundation of the Societas State Secretary at the Federal Meteorologica Palatina. Germany thus has a particularly long tradition of Ministry of Transport, Building and systematic and standardised recording of climate-relevant parameters. In a Urban Development (BMVBS) federal country, such as Germany, for example, where the responsibilities for monitoring the different components of the climate systems are distributed among the Federation and the Länder, it therefore is of paramount importance to have an inventory of all ongoing measuring and observing programmes. The present report gives for the first time a full overview of all programmes running in Germany to collect climate variables that are relevant to our country. Selection of the variables was made according to the list of ‘Essential Climate Variables’ (ECV) issued by the Intergovernmental Panel on Climate Change (IPCC) and the Global Climate Observing System (GCOS). This report will make a contribution to generally facilitating the access to these data and their interdisciplinary use.

3 Summary

The foundations for all observation Even though not all relevant of meteorological phenomena on a data are available at national level global scale were laid in 1780 with in a standardised form, the wealth the foundation of the Mannheim of measured data allows for most Societas Meteorologica Palatina. So accurate statements on the climate Germany has a very long tradition in Germany and its development. of climate observation, including The challenges ahead are to the longest time series of near-sur- further standardise observing systems face temperature and air pressure and ensure the availability of Germany- taken at the world’s oldest mountain wide data, together with fulfilling the station at Hohenpeissenberg since Herculean task of digitizing existing 1781. Furthermore, there are con- historical paper data. tinuous monthly climate data avail- A necessary prerequisite to able starting in 1881 in the form of efficiently and sustainably implement precipitation amounts from 59 sta- the German Action Plan for Adaptation tions and mean temperatures from under the German Adaptation 43 stations. Strategy of the Federal Government Germany holds long time series is to have an integrated view of all of atmospheric and hydrological relevant climate variables. climate variables, the continuation of This inventory report on national which is well secured into the future. climate observing systems gives a However, sustainability is not always detailed overview of climate-relevant secured especially for ocean and ter- variables of atmosphere, ocean and restrial observations. land measured in Germany. It is the first ever broad compendium of Ger- man climate observation addressing to climate research and decision- makers.

4 Zusammenfassung

Die 1780 in Mannheim gegründete Die weitere Standardisierung der Societas Meteorologica Palatina Messverfahren und die Bereitstel- legte den Grundstein zur globalen lung ganz Deutschland abdeckender Wetter- und Klimaüberwachung. Aus Datenreihen stellen zusammen mit diesem Grund verfügt Deutschland der Herkulesaufgabe der Digitalisie- am Hohenpeißenberg, die älteste rung historischer Papierdaten die Bergstation der Welt, über eine seit Herausforderungen der näheren 1781 durchgehende Zeitreihe der Zukunft dar. bodennahen Lufttemperatur und des Eine integrierte Sicht auf alle für Luftdrucks. Außerdem liegen seit Deutschland relevanten Klimavariab- 1881 durchgehende Monatsdaten len ist eine notwendige Vorausset- von immerhin 59 Stationen zur Nie- zung um den Aktionsplan Anpassung derschlagssumme und 43 Stationen im Rahmen der Deutschen Anpas- zur Mitteltemperatur vor. sungsstrategie der Bundesregierung Deutschland verfügt im Bereich effektiv und nachhaltig umsetzen zu der atmosphärischen und hydrolo- können. gischen Klimadaten über lange und Der vorliegende Inventarbericht weitestgehend auch für die Zukunft der nationalen Klimabeobachtungs- gesicherte Beobachtungsreihen. Vor systeme gibt einen detaillierten allem bei Ozeanbeobachtungen und Überblick über die hierzulande ge- einigen terrestrischen Beobachtun- messenen klimarelevanten Größen gen ist die Nachhaltigkeit jedoch in Atmosphäre, Ozean und im nicht ausreichend gesichert. Bereich der Landoberflächennutzung Auch wenn längst nicht alle und stellt somit erstmals ein breitge- Daten deutschlandweit standardi- fächertes Kompendium über Klima- siert verfügbar sind, können – basie- beobachtungen in Deutschland für rend auf instrumentell erhobenen Klimaforschung und Entscheidungs- Daten – hinreichend genaue Aussa- träger bereit. gen über den Verlauf des Klimas in Deutschland gemacht werden.

5 Contents

Introduction

8 2 3 4

Atmospheric Ocean Terrestrial observations observations observations

Near surface Sea surface Hydrosphere

2.1 Temperature 14 3.1 Ocean temperature 44 4.1 Runoff 62 2.2 Wind 16 3.2 Salinity 46 4.2 Water use 64 2.3 Air pressure 18 3.3 Sea level 48 4.3 Groundwater 66 2.4 Precipitation 20 3.4 Sea state 50 4.4 Stable isotopes 2.5 Radiation 24 3.5 Sea ice 52 in precipitation 68 2.6 Sunshine duration 26

Free atmosphere Open ocean Cryosphere

2.7 Temperature, wind 3.6 Deep water formation 54 4.5 Snow cover 70 and water vapour 28 4.6 Glaciers and permafrost 72 2.8 Clouds 30

Atmosphere composition Ocean composition Biosphere

2.9 Carbon dioxide 32 3.7 Ocean colour 56 4.7 Albedo 74 2.10 Methane 34 3.8 Nutrients in the ocean 58 4.8 Soil carbon 76 2.11 Other greenhouse gases 36 3.9 Oxygen conditions 4.9 Forest fires 78 2.12 Ozone 38 in the North Sea 60 4.10 Soil moisture 80 2.13 Aerosols 40 4.11 Phenology 82 2.14 Pollen 42

6 5 6 7

International Observations Conclusions data centres abroad and outlook

5.1 Global Precipitation 6.1 Ozone soundings at 112 Climatology Centre (GPCC) 84 Neumayer station in the Antarctic 102 5.2 Global Runoff Data Centre (GRDC) 86 6.2 Glacier monitoring abroad 104 5.3 World Radiation Monitoring Center (WRMC) 88 6.3 International tide gauge observations 106 5.4 World Data Center

for Climate at the German 6.4 CO2 partial pressure Climate Computing Centre in the ocean 108 (WDC-Climate) 90 6.5 Deep ocean currents 110 5.5 World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT) 92 5.6 Global Fire Monitoring Center (GFMC) 94 5.7 ICSU World Data Center PANGAEA® 96 5.8 Data quality assurance centres of GCOS 98 5.9 Satellite Application Facility on Climate Monitoring (CM SAF) 100 Annexes

List of authors 118 Literature 120 Abbreviations 122 Picture credits 128

7 1. Introduction

Since the adoption of the Framework Convention on Climate Change (UNFCCC) at the Earth Summit in Rio de Janeiro in 1992, climate protection has become a major focus of public attention. However, decision-making for climate protection and adaptation to the unavoidable climate change requires long-term high-quality observations of the main climate parameters. With this aim in mind, the Global Climate Observing System (GCOS) was established shortly after the Rio Earth Summit. The objective of GCOS is to enhance climate observation around the world, taking account of users’ requirements.

Climate system and climate Observations – in this case of the observations climate system – allow researchers ‘Climate’ is generally understood as to develop model-like visions of the the average of weather conditions interactions and their effects. Under- observed at a certain place over a standing this is the prerequisite that sufficiently long period of time to be enables us to reconstruct the obser- described using statistical values. vations by means of mathematical/ The internationally agreed period of physical models (i.e. climate models), time over which statistical values, to validate predictions and, on this such as means and averages (e.g. of basis and taking into account certain near-surface temperature), frequen- assumptions, to produce reliable cies (e.g. the exceeding or not of projections of future developments. thresholds) or extremes, are calcu- The four assessment reports lated is 30 years. As a rule, the longer (1990, 1995, 2001, 2007) by the the periods under examination, the Intergovernmental Panel on Climate more representative the statistical Change (IPCC) give evidence of how statements are. our knowledge of the climate system The climate in a certain place and climate modelling has developed depends on a number of processes over the last decades. Many of the and developments. To understand the new findings that aid our understand- interrelationships that make up the ing of the climate system as well as climate system, not only the state of the ensuing model improvements the atmosphere needs to be observed result from the availability and exten- and described over long time periods sive analysis of observational data. but also the state of the oceans and The IPCC’s first assessment land surfaces and all related changes. report had already pointed out the The climate system consists of the necessity of improving systematic atmosphere, oceans and land surface. observation of climate-relevant With many changes in these compo- parameters at the global level (IPCC, nents being influenced or even trig- 1990). The participants of the Second gered by man, socio-economic facts World Climate Conference (WCC-2) must also not be ignored. The graphic then called for the establishment of on page 9 gives an overview of the a ‘Global Climate Observing System’ physical, chemical and biological (WMO, 1990). As a result, the Global interactions in the climate system. Climate Observing System (GCOS)

8 1 Introduction

s Components of the climate system and their physical, chemical and biological interaction Source: DWD

was jointly established in 1992 by pheric, oceanic and land variables the World Meteorological Organiza- need to be collected. To obtain tion (WMO), the United Nations exact estimations of temporal Environment Programme (UNEP), parameter variability and attribute the Intergovernmental Oceanographic the causes, the measurement Commission (IOC) of the United series must be highly accurate, Nations Educational, Scientific and with good homogeneity and long- Cultural Organization (UNESCO) and term continuity. the International Council for Science (2) Monitoring the forcing of the (ICSU). Since then, various reports climate system, including both have been compiled within the natural and anthropogenic scope of GCOS to analyse the state contributions: of global climate observing systems, In the past centuries and millen- elaborate plans for remedying defi- nia, climate variability resulted ciencies in the observing systems, from variations in natural factors and document the progress made in such as solar irradiation and the implementation of these plans. volcanic activity. Today, anthropogenic causes, such as greenhouse Requirements for climate gas emissions and air pollution observations as well as changes in land use, The basic requirements to be met by add to these. the GCOS programme were speci- (3) Supporting the attribution of the fied at the time of the system’s causes of climate change: foundation in 1992. A more sophis- Climate monitoring as described ticated definition of these require- in (1) and (2) also helps to im- ments was presented in a detailed prove the understanding of the report on the adequacy of global interactions between different climate observing systems (WMO, elements and attribute the causes 2003a). The requirements are of changes. This is done by using grouped as follows: the observational data to develop (1) Characterising the state of models for investigating in experi- the global climate system and its ments the causes and interrela- variability: tions and enable anthropogenic In order to describe the climate and natural causes to be differen- system, a wide variety of atmos- tiated.

9 Climate component Essential Climate Variables

Atmosphere Surface Air temperature, precipitation, air pressure, surface radiation balance, wind speed, wind direction, water vapour Free atmosphere Radiation balance (including solar radiation), temperature, wind speed, wind direction, water vapour, clouds Composition Carbon dioxide, methane, ozone, other greenhouse gases, aerosols, pollen Oceans Surface Surface temperature, salinity, sea level, sea state, sea ice, currents, water colour, partial pressure of carbon dioxide Intermediate and Temperature, salinity, currents, nutrients, carbon, deep waters trace substances, phytoplankton Land surface Runoff, lakes and seas, ground water, water use, isotopes, snow cover, glaciers and ice caps, permafrost, albedo, land cover (including type of vegetation), leaf area index, photosynthetic activity, biomass, forest fire, soil moisture, phenology

GCOS Climate Monitoring Principles

1. The impact of new systems or changes to existing systems should be assessed prior to implementation. 2. A suitable period of overlap for new and old observing systems is required. 3. The details and history of local conditions, instruments, operating procedures, data processing algorithms and other factors pertinent to interpreting data (i.e. metadata) should be documented and treated with the same care as the data themselves. 4. The quality and homogeneity of data should be regularly assessed as a part of routine operations. 5. Consideration of the needs for environmental and climate-monitoring products and assessments, such as IPCC assessments, should be integrated into national, regional and global observing priorities. 6. Operation of historically-uninterrupted stations and observing systems should be maintained. 7. High priority for additional observations should be focused on data-poor regions, poorly-observed parameters, regions sensitive to change, and key measurements with inadequate temporal resolution. 8. Long-term requirements, including appropriate sampling frequencies, should be specified to network designers, operators and instrument engineers at the outset of system design and implementation. 9. The conversion of research observing systems to long-term operations in a carefully-planned manner should be promoted. 10. Data management systems that facilitate access, use and interpretation of data and products should be included as essential elements of climate monitoring systems.

10 1 Introduction (4) Supporting the prediction of levels. In Germany, these include global climate change: pollen, isotopes in precipitation and Climate prediction requires us to phenological parameters. look not only at the development To make sure that long time of the factors referred to in (2), series of national in situ observations but also at the initial state of the take account of large-scale changes climate system. In addition, long only, if possible, and that these are data series of the main climate comparable at international level, variables help us to assess and GCOS has laid down ten basic prin- further develop climate models. ciples for monitoring the climate, (5) Projecting global climate change known as the GCOS Climate Monitor- information down to regional ing Principles (see Table 2, Karl et al., and national scales: 1995; WMO, 2003a). The effects of climate change and Germany has a long tradition of Table 1: adaptation to them require action climate observation. The foundations Essential Climate Variables (ECVs) in accord- particularly at national and regional date back to Alexander von Humboldt ance with the GCOS Implementation Plan level. This is why additional, more (1769–1859) and to around 1780, (WMO, 2010) as well as those variables that are detailed information is needed at when the Societas Meteorologica additionally relevant to Germany (in italics) this level to complement the Palatina, also known as the Meteoro- variables mentioned under (1) in logical Society of Mannheim, came order to develop regional climate into existence. Since then, German models and better understand institutions have contributed to sys- how the climate affects natural tematic observation of the climate systems. system at national and international (6) Characterising extreme events level. for the assessment of impacts, Systematic observation activities risk and vulnerability relevant to Germany currently com- Climate observation data are prise almost all ECVs (see Table 1). aimed at enabling classification The data are generally subject to of extreme events, such as flood- strict quality checks and are, for the ing, heat and storms, in order to most part, transmitted to international run corresponding impact analy- data centres, some of which are oper- ses and work out guidelines, ated by German institutions. From adaptation strategies and action there, they are available to internation- plans. al research groups for integrated In order to satisfy these requirements, global studies, notably on climate GCOS has defined, in co-operation change, and to operational institu- with the IPCC and the World Climate tions. German institutions thus help Research Programme (WCRP), a to improve international collabor- number of essential climate variables ation and standardisation of measure- (ECVs, see Table 1). Further to the ment data. scientific requirements, the selection In order to co-ordinate national has also taken into account the ex- efforts and support the international tent to which observation of these activities of GCOS, a national GCOS ECVs can be implemented on a global Secretariat for Germany was in- scale for the purposes of climate stalled a the Deutscher Wetterdienst monitoring. New research findings, (DWD) as early as in autumn 1992, advances in measurement technol- immediately after the establishment ogy and new user requirements, may of the GCOS programme. Shortly enable new variables to be included, after that, the brochure ‘GCOS – The Table 2: if needed. German View’ was published, giving The ten Principles were considered at the Along with the global ECVs, a first overview of German contribu- 5th Conference of the Parties (COP 5) to the which were first defined in 2003, it tions to GCOS. United Nations Framework Convention on may be necessary to observe other Since 1998, national GCOS meet- Climate Change (UNFCCC, 2000) and adopted climate variables at a national level, ings have taken place to enhance by the 14th WMO Congress in May 2003 which are not part of the ECVs but co-operation between all institutions (WMO, 2003b). have been recorded for a long time in Germany that are responsible for on a systematic basis and have been making climate observations and to of significance for characterisng the co-ordinate German contributions to climate and its variability at local GCOS.

11 The purpose of this report at the international level; they are Historically, Germany has a very designed as a summary of the con- long tradition of observing climate- tributions Germany makes to global related parameters. The collection of observation networks. historical data represents a veritable With a view to providing the first treasure trove for the responsible ever comprehensive and descriptive institutions and bodies, which is of survey of climate observation in great scientific significance for cli- Germany, it was agreed at the 6th na- mate research at national and inter- tional GCOS meeting held in March national level. These data are one of 2011 to publish a special brochure our cultural assets which, if lost, can on climate observations in Germany. never be recovered again. A good example here is the inventory Preserving and continuing long report of the Swiss government time series of observations is a con- entitled ‘National Climate Observing tinuous challenge for all those who System (GCOS Switzerland)’ (Seiz bear the responsibility. Particularly and Foppa, 2007). at risk are those observation series the collection of which depends on Structure of the report temporally limited research funds. Essential climate variables are pre- Another, different kind of risk sented separately, with some com- results from the fact that many data bined into one section if closely still only exist in paper form or on related. Chapters 2 to 4 deal with the old data storage devices and thus atmospheric and oceanic variables are not available for modern analy- and terrestrial observations. sis. Without any counter measures, The description of each parameter there is a risk of losing these histor- is complemented by information ical data forever. about the legal framework, observed In addition, the monitoring of cli- trends, international context and mate-related parameters in Germany scientific significance as well as the is distributed among multiple re- resources needed. Chapters 5 and 6 search institutions and authorities at describe the international data centres federal and regional levels. The existing in Germany and Germany’s purpose of this report is to provide observation activities abroad or out- an overview of the current situation side its territorial waters. Chapter 7 and information about the sustain- closes the report by summarising the ability of these observations into the major findings and giving an outlook future. A particular focus will be on the future of Germany’s national given to data sets at possible risk. climate observing system GCOS-DE.

Methodology of the report Under the commitments of the UNFCCC, the Federal Government regularly draws up national inventory reports on the activities undertaken by Germany towards the implementation of the Convention. The reports all have a chapter describing research and systematic observation measures in Germany. The 3rd Nation- al Report (Bundesregierung, 2002) was the first to give a more detailed presentation of Germany’s contribution to systematic climate observation. The 5th National Report incorporates, for the first time, an entire report of its own about Germany’s contribution (Deutscher Wetterdienst, 2009). All these reports give only a very broad overview which follows a very strict structure to enable comparison

12 1 Introduction

s BSRN observation field at AWI Neumayer station in the Antarctic (BSRN = Baseline Surface Radiation Networks, AWI = Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research)

13 2.1 Temperature

Temperature is one of the main indicators for describing the climate and its variability. In the context of expected anthropogenic climate warming the observation and analysis of this parameter is of special importance.

Climate trends The times series of area averages derived from the gridded fields allow meteorologists to discern climatological trends regardless of any lack of homogeneity that might exist in the records of single stations. They reveal a warming of about 1.1°C (linear trend) during the last 130 years. However, this trend is not uniform over the entire time series. Instead, there was an increase in temperature Measurements in Germany up into the 1940s, followed by a The Deutscher Wetterdienst (DWD) decrease until around 1970 and then operates a network of weather and a very pronounced increase until the climate stations, of which about year 2000. In the last decade, the 500 currently measure temperature. annual mean temperature remained This dense network has existed for at this high level. Thus, the time about 60 years. series for Germany widely corres- Alongside the DWD stations, ponds to the global trend, but with a additional measurements of tem- somewhat stronger warming. perature are taken by other institutions and individual persons. However, only minor parts of these series are included in the DWD’s database, as they often do not meet the high standards of representativeness, measurement methods or continuity of operation. Before 1950, the number of stations was considerably lower and often only monthly data exist, Legal framework which have now been digitised up Before that date, only a few sin- The Law on the Deutscher Wetter- to World War II. But many of the gle time series exist, which often dienst (§ 4) gives the DWD responsi- daily values have been lost. lack homogeneity due to differences bility for short- and long-term regis- Monthly values are available from in measurement methods and obser- tration, monitoring and evaluation of a relatively dense network of more vation programmes. The longest of meteorological processes as well as than 130 stations dating back to these time series (Berlin) dates back the structure and composition of the 1881, thus enabling grid fields to to 1719. atmosphere, and for the operation be compiled (by interpolation) and A first uniform and well-docu- of the required measurement and spatial mean values to be mented network was established in observing systems. computed. 1781 in the context of the Societas

14 2 Atmospheric observations Near surface Annual mean temperature for Germany for the period 1881–2011

s The time series shows a significant temperature increase, especially in the 1980s and 1990s, of nearly 1°C higher than in the period 1961–1990.

Meteorologica Palatina by the prince- International context Required resources elector of the Palatinate. This network The synoptic reports from 180 sta- Because of the legal mandate given collapsed after about ten years in the tions are distributed worldwide on a to the DWD the operation of the turmoil of the French Revolution and routine basis. For a selected number existing measuring stations can gen- the following wars. But some of the of these stations, quality-checked erally be considered as secured. But observers continued their measure- monthly climatological information to meet the requirements to save ments, providing continuous clima- is made available in the form of resources, the DWD continues to tological time series, such as the one CLIMAT reports. The stations at optimise and automate its networks. for Hohenpeissenberg near Weilheim Frankfurt, Hamburg, Hohenpeissen- The continuation of long time series in the Alpine foothills since 1781, berg and Lindenberg are part of the at selected climate reference stations which could be successfully hom- GCOS Surface Network (GSN). is secured. Manning of stations will ogenised to a large extent. be further reduced and be limited to Between 1995 and 2005, in the stations at airports and to reference context of the general automation of stations. Current digitisation activities the networks, the equipment used must be continued in order to make for measuring temperature widely further long time series available. changed from mercury thermometers and bimetal recording instruments to digital electronic thermometers. Fortunately, no significant inconsistencies in the time series of monthly and annual means resulted. At eleven reference stations, where long time series exist, conventional analogue measurements continue to be taken in parallel with the new digital measurements by automatic systems. http://www.dwd.de

15 2.2 Wind

Wind is an essential indicator for describing the climate for the purposes of different areas of application. Its importance is growing particularly in the context of the use of renewable energies, but also because of the potential for damage during extreme storm events.

Legal framework The Law on the Deutscher Wetter- dienst (§ 4) gives the DWD responsibility for short- and long-term registration, monitoring and evaluation of meteorological processes as well as the structure and composition of the atmosphere, and for the operation of the required measurement and observing systems.

Measurements in Germany The Deutscher Wetterdienst (DWD) operates a monitoring network of weather and climate stations, of which about 300 currently take wind speed and wind direction measurements. This dense network has existed for about 20 years. Going back to before that time, the coverage of wind measurements becomes gradually coarser; however, there are wind estimates available from secondary stations. From before 1950, there exist only a few single measurement series. Some time series of wind estimates go back to the 19th century. Due to different measuring and evaluation methods, the longer time Wind stations in Germany (2011) series often contain considerable inconsistencies, but which can partly be corrected regarding the wind speeds.

16 2 Atmospheric observations Near surface Annual means of geostrophic wind in the German Bight

s Annual means of geostrophic wind speed in m/s in the German Bight for 1881–2011 with 10-year moving average (September to August)

Climate trends There are no clear trends to be seen from the station time series for wind speed. Longer time series derived from air pressure measurements (geostrophic wind) also show no significant trends. But it appears that International context Germany experiences an oscillation The synoptic reports (including wind of weaker and stronger wind speed measurements) from 180 stations are periods with a periodicity of about distributed worldwide on a routine 40 years. For the area of the German basis. For a selected number of these Bight, there is evidence of a phase of stations, quality-checked monthly low wind speed in the 1960s and climatological information is made 1970s, while the 1980s and 1990s available in the form of CLIMAT saw a slight increase in wind speed. reports. The stations at Frankfurt, Hamburg, Hohenpeissenberg and Lindenberg are part of the GCOS Surface Network (GSN).

Required resources The operation of the existing measuring stations can generally be considered as secured.

http://www.dwd.de

17 2.3 Air pressure

Air pressure is one of the main indicators for describing the climate as its spatial distribution determines the general circulation of the atmosphere. It is the variable which characterises the high and low pressure areas that influence the weather.

Climate trends The time series of air pressure reveal no significant climate trends, although, with the exception of the years 2009 and 2010, the last three decades are characterised by relatively high air pressure (see graph on page 19). However, there are currently no statistical trend analyses of air pressure for the entire area of Germany available. Earlier studies (Schön- wiese and Rapp, 1997) of 100- and 30-year time series show largely varying seasonal patterns. The warming in winter during the last decades of the 20th century Legal framework is apparently not only accompanied Measurements in Germany The Law on the Deutscher Wetter- by a strengthening of the zonal As the spatial distribution of air pres- dienst (§ 4) gives the DWD responsi- westerlies over Europe but also by sure generally is quite homogenous, bility for short- and long-term regis- a northward shift of the subtropical the network of measurement sta- tration, monitoring and evaluation of high and thus an increase in surface tions requires here a lower density meteorological processes as well as pressure over central Europe. than for other climate variables. The the structure and composition of the Air pressure changes are often Deutscher Wetterdienst (DWD) atmosphere, and for the operation of manifested through changes in the operates a network of weather and the required measurement and frequency and intensity of large- climate stations, of which about 180 observing systems. scale weather patterns (known as currently take air pressure measure- ‘Großwetterlagen’). For example, ments. This network has existed for periods of dry weather are usually about 60 years. associated with high pressure sys- Going back to before 1950, the tems, rainy periods with low pres- station density was much coarser; sure activity. A trend in the climate from before about 1930, there exist variable air pressure can therefore only a few single measurement explain changes in other climate series which often contain inconsist- variables, but not give the reasons. encies due to different measurement methods and observation programmes. A first uniform and well documented network was established in 1781 in the context of the Societas Meteorologica Palatina by the

18 2 Atmospheric observations Near surface Annual mean air pressure deviation in Frankfurt am Main for the period 1951–2011

s Negative (dark green) and positive deviations (light green) from the long-term mean air pressure at sea level (1961–1990)

International context The synoptic reports from 180 stations are distributed worldwide on a routine basis. For a selected number of these stations, quality-checked monthly climatological information prince-elector of the Palatinate. is made available in the form of This network collapsed after about CLIMAT reports. The stations at ten years in the turmoil of the Frankfurt, Hamburg, Hohenpeissen- French Revolution and the follow- berg and Lindenberg are part of the ing wars. But some of the obser- GCOS Surface Network (GSN). vers continued their measurements, providing continuous climatological time series since 1781 such as the one for Hohenpeissenberg near Required resources Weilheim in the Alpine foothills. Because of the legal mandate given Between the years 1995 and to the DWD, the operation of the 2005, in the context of the general existing measuring stations can gen- automation of the networks, the erally be considered as secured. A measurement equipment changed systematic continuation of the digit- from manually operated mercury isation activities is required to make barometers and analogue aneroid further long time series available for barometers to digital devices. For- scientific assessments and model- tunately, no significant inconsisten- based reanalysis. cies in the time series were found.

http://www.dwd.de

19 2.4 Precipitation

Alongside temperature, precipitation is the key indicator for describing the climate and its variability. It is also an important parameter for both water cycle and water budget, with accordingly high relevance for agriculture and water management. Thanks to its climate data archive, the Deutscher Wetterdienst (DWD) can provide reliable analyses of the spatio-temporal behaviour of precipitation back to the year 1881 also in the context of anthropogenic climate change. For the most recent decades, precipitation data collected by remote sensing add to the ever-growing number of in situ measurements of high temporal resolution.

Climate trends the minute range (see top graph on The grid-based reanalysis of in situ page 23). Moreover, more than 1,000 precipitation measurements allows of the stations have already been for discerning climatological trends changed to automatic measurement since 1881 irrespective of any incon- methods. Most non-automated sta- sistency that might exist in the time tions used to and continue to record series of single stations (see graph one daily measurement (at 7:00 am), on page 21). The average annual pre- whereas until 2000 all of the nearly cipitation in Germany shows an in- 500 climate stations registered three crease of 10% over the last 130 years. measurements per day, at 7:00, The increase is concentrated in the 14:00 and 21:00 LMT. Since that date, winter half-year, whereas the summer all climate stations have successively half-year totals do not show any been automated. In addition to these, significant trends. This national trend Precipitation stations of the DWD several hundred analogue rain can differ in magnitude – and sign – Other precipitation stations gauges provide hourly precipitation in specific regions and by season. s totals. Precipitation stations included in the DWD This dense daily precipitation archive (as of August 2012) measurement network has been operated this way for approximately Measurements in Germany 60 years and comprised from 1951– Legal framework The DWD operates a network of 2004 (1969–2000) more than 3,000 The Law on the Deutscher Wetter- around 2,000 weather and climate (4,000) stations (see top graph on dienst (§ 4) gives the DWD responsi- observation stations (see map page 23). Most of the stations, how- bility for short- and long-term regis- above), where precipitation data ever, were manned, which made a tration, monitoring and evaluation of are collected at least on a daily- high demand on human resources. If meteorological processes as well as total basis. Since around 1995, only monthly totals are required, the the structure and composition of the precipitation measurements have DWD has recourse to a network of atmosphere, and for the operation of been taken increasingly by digital more than 2,000 stations with data the required measurement and systems allowing for improved records going back the last 100 years; observing systems. temporal resolution – even into to find fewer than 1,000 stations, one

20 2 Atmospheric observations Near surface Average annual precipitation totals for Germany 1881–2010

s Average annual precipitation totals based on an ensemble of about 400 German precipitation stations

has to return more than 120 years International context Required resources back to 1891. Extending the period Besides to other data centres, all The sustained operation of existing for another ten years back to 1881, data registered at the precipitation measurement stations can be re- there is still a network of several hun- stations are forwarded to the Global garded as substantially secured. dred stations available, good enough Precipitation Climatology Centre, However, the level of automation to interpolate reliable monthly gridded hosted by the DWD (see Chapter 5.1). must be driven further, the high fields and area totals. Before 1881, Moreover, the precipitation param- number of staff further reduced and the availability of time series is spor- eter is one of the nine essential limited to observations at air fields adic and lacks homogeneity due to climate variables (ECVs) which the and climate reference stations. Pre- differences in measurement methods DWD processes as part of its function cipitation monitoring in the era of and observation programmes. as Regional Climate Centre on climate change needs to work at Alongside the DWD stations, Climate Monitoring (RCC-CM) of the high levels of resolution and avail- there exist additional precipitation Regional Association VI (RA VI, ability and comprise Germany and measurements which are carried out Europe) of the World Meteorological its adjoining relevant river catch- by other institutions or individual Organization (WMO). The DWD is ments; it requires at the same time persons. However, only minor parts actively engaged in international the sustained operation of reference of these series are included in the bodies (e.g. WMO and EUMETNET/ stations with essential (i.e. long) DWD’s database, as they often do not ECSN as well as GMES, GEO, measurement series. Persistent data meet the high standards of represen- GEOSS), which reflects its significant digitisation activities are required in tativeness, measurement methods status in the fields of European and order to make further long data or continuity of operation or are just global climate monitoring. series available for scientific studies. not available to the DWD.

http://www.dwd.de

21 2.4 Precipitation

Significance of long data series trained weather observers using Africa, China and the tropical Pacific Systematic, station-based recording conventional measuring and obser- (Bismarck Sea) and the southern of precipitation in Germany and the vation techniques. At least ten years Pacific. Their complete digitisation operation of the corresponding sta- of comparative measurements will will require about another 40 person- tion networks are closely connected prevent misinterpretation of the data years. to the institutions and bodies that series collected by the DWD with Within the framework of the operate them. The result is a hetero- regard to climatological and climate analysis of short-duration extreme geneous picture in terms of geog- change issues. With its climate ref- precipitation, the DWD has digitised raphy and time, given the fact that erence stations system, the DWD the pluviograph records of around the first national meteorological has taken a pioneer role and is a 200 stations. The resulting data service, the Reichswetterdienst‚ did renowned contact for many Euro- series are of different lengths; they not come into existence until 1934. pean meteorological services. The all start no earlier than 1951. For 60 Before then, and until the foundation ultimate goal is to build a similar of the 200 station data series, digit- of the DWD, precipitation observation Europe-wide network of climate ref- isation could be extended until 2010. was the responsibility of regional me- erence stations. The sites chosen by teorological services or the meteoro- the DWD (see map below) are char- logical services of the Länder, which acteristic of their geographic and cli- New requirements resulting is the reason for the multitude of matic environment. from anthropogenic climate networks. The longest uninterrupted change precipitation time series in Germany Data rescue projects of the DWD In the context of the expected anthro- started at the station in Aachen in Since early 2005, the DWD has been pogenic global warming, the rele- 1844, originally operated by the Royal running the KLIDADIGI project to vance and requirements of quality Prussian Meteorological Institute digitise historical daily precipitation and geo-temporal resolution of the and which has, for this reason, been data existing only on paper in order monitoring of variability and trends designated as one of the eleven cli- to make them available for climate in precipitation, regional particular- mate reference stations of the DWD. monitoring and research, in particu- ities included, have further grown. lar with regard to climate change, For example, adaptation to changing DWD climate reference stations and to rescue them from their ultim- hydro-meteorological conditions The progressing automation of ate disintegration and loss. The constitutes one of the major chal- weather observation calls for inves- green shaded area in the top graph lenges in enhancing the resilience of tigation and quantification into the on page 23 shows the number of societies to the impact of climate impact of the switch to digital record- precipitation stations with monthly change. ing methods on data series. At values, but which also hold daily Due to their high accuracy and eleven climate reference stations in data yet to be digitised, in contrast to the length of time series, station- Germany, digital recording takes the comparatively small amount of based precipitation data continue therefore place parallel to manual daily precipitation data already digit- to be the back-bone of precipitation observations carried out by well- ised up to August 2011 (red area). monitoring. With station-based data, Digitisation of the paper documents however, there are the problems of covering the whole 165,000 precipi- representativeness and homogeneity. tation station-years plus a total of Moreover, even the national network 23,000 station-years from DWD cli- of more than 4,000 stations that was mate stations would require a work operated in the years 1969–2000 was force of 790 person-years. Between nowhere near dense enough to de- now and 2025, the DWD plans to tect extreme, small-scale precipitation digitise, and thus rescue, about 25% events. This problem of detection is of these documents, with a major worse in remote regions where the focus on the longest and most com- question of inaccessibility leads to plete series. reduced density of stations. This is Further worldwide historical pre- sufficient reason to use remote cipitation records from more than sensing (satellite and radar)-based 1,500 overseas stations have been precipitation measurements also for made available by the Hamburg- hydro-climatological applications, based Deutsche Seewarte (German although at least the radar-based Maritime Observatory). The majority measurements had originally been of these mostly 12-hourly measure- introduced for real-time applications ments (taken twice per day) cover the only. Meanwhile, satellite- and radar- periods 1884–1918 and 1930–1943, based precipitation data sets have s with the stations spread across all respectively entered the multi-decadal Position of the eleven climate reference continents, mainly in the former and decadal scales in temporal stations of the DWD German colonies and protectorates in coverage and exist at geo-temporal

22 2 Atmospheric observations Near surface resolutions in the hourly and kilo- Temporal coverage of precipitation data at monthly, daily and minute scale, complemented by daily metre scales, thus offering the totals from the KLIDADIGI project potential for high-resolution precipitation reanalysis for climatological purposes through means, variances, extremes and trends.

Radar-based quantitative precipitation monitoring The DWD’s RADOLAN software system for real-time online calibration of radar-based quantitative precipitation data by means of automated surface-based rain gauges supplies high-resolution quantitative precipitation data for the whole of Germany in real time. The real-time calibration takes place on the basis of precipitation data collected in the DWD’s operational radar network of 17 C- band Doppler radar devices (see map below) and the in situ measurements rain gauges) had already been avail- from the network of automated able since January 2001, the DWD is gauges jointly operated by the DWD currently running a decadal, geo- and the German Länder (see map on temporally homogeneous and high- the right). In standard mode, the resolution quantitative precipitation ‘precipitation scan’ provides precipi- reanalysis covering the period from tation data in 5-minute intervals, 1 January 2001 until the present covering a radius of 150 km max- day. This will lay the foundation for imum around the radar site. The a nationwide radar-based precipita- hourly in situ precipitation totals of tion climatology that is updated on more than 800 automated DWD rain a regular basis. gauges and about 300 auxiliary stations operated by the Länder are utilised for online calibration of the Direct measurements radar data. taken at sea The RADOLAN software system Although the code for the dissemin- has been in operation since 2005 and ation of meteorological data at sea has since been enhanced several includes precipitation as a parameter times. As the input data (radar and of observation, the fleet of volun- tarily observing ships, buoys and lightship substitution systems in the North and Baltics Seas does not register precipitation due to the lacking reliability of such measurements. The continuous movement s of the vessels driven by wind and Map of automated rain gauges of the DWD and waves strongly affects the measure- the German Länder (blue dots) ments, as does spray. Among the German research ships, FS Polarstern and FS Meteor are equipped with rain gauges, although their data records are also prone to error and too incomplete to be used for climatological assessment.

C-band radar network of the DWD (station radius: 150 km)

23 2.5 Radiation

The radiation balance at the earth’s surface is an important factor in the energy budget of the earth-atmosphere system. Spatial and temporal differences in the radiation balance generate the weather and have a decisive influence on our climate. Global radiation, one of its most important and most commonly measured components, is the amount of energy potentially available at the earth’s surface from our principal energy source, the sun, for all weather and life processes, as well as for technological uses.

Climate trends Only continuous measurements over long periods of time allow conclusions to be drawn about climate change. To this end it is important to analyse changes in radiation parameters in relation to other meteorological variables and/or environmental parameters measured at the same station. There are measurement series of global radiation spanning 50 or more Radiation from the lower atmos- years at nine stations. Examples of phere, reflected short-wave radiation annual amounts of global radiation and long-wave thermal radiation from four stations in different cli- emitted from the earth’s surface are mate zones are shown in the graph currently recorded only at the bound- on page 25. Regional differences are ary-layer field site of the Lindenberg clearly visible, but also the worldwide Meteorological Observatory – Richard phenomenon of ‘global dimming’ Assmann Observatory (MOL-RAO), that occurred in the middle of the which is in continuous operation Measurement of global and diffuse solar radiation 1980s and the subsequent ‘global 24 hours a day. Measurement of global and diffuse solar radiation brightening’. and atmospheric thermal radiation The earliest (quasi-)continuous In this respect, it is worth noting measurement of global radiation that complex climatological analysis dates from 1937, when it was initiated is particularly reliant on long time Measurements in Germany at the former Potsdam Meteorological series of relevant meteorological Continuous, comprehensive record- Observatory. The International Geo- parameters from reference weather ing of short-wave global radiation and physical Year (IGY) of 1957–58 pro- stations. long-wave atmospheric thermal radi- vided the impulse for the establish- ation, which are the most important ment of a global radiation measure- components of the radiation balance, ment network in Germany consisting is currently undertaken using pyrano- of ten stations; one of the key aims Legal framework meters by the DWD’s ground-based of the IGY was to promote radiation The Law on the Deutscher Wetter- observing network at 26 manned measurement for the study of the dienst (§ 4) gives the DWD responsi- stations, which also measure diffuse conversion of energy in the earth- bility for short- and long-term regis- solar radiation. Twelve of these sta- atmosphere system and its spatial tration, monitoring and evaluation of tions also measure atmospheric ther- and temporal variation. The network meteorological processes as well as mal radiation using pyrgeometers. in Germany has expanded over the the structure and composition of the Samples at 1 Hz are taken from all course of time. Modernisation has atmosphere, and for the operation of radiation measurement devices also taken place, from the adoption the required measurement and around the clock and one-minute of a stand-alone system with plotter observing systems. averages are stored in the database. to the current system of electronic

24 2 Atmospheric observations Near surface Annual amounts of global radiation and 11-year moving averages

s Annual amounts of global radiation (G, in MJ/m2) and 11-year moving averages (gl) from stations at Hamburg (HH: 1949–2011), Potsdam (PO: 1937–2011), Würzburg (WZ: 1957–2011) and Weihenstephan International context (WN: 1961–2011) The IGY played an important role in promoting global co-operation in the radiation sector. Since 1964, radiation data obtained by the DWD network have been regularly transmitted to the World Radiation Data data capture and centralised trans- Centre (WRDC) set up by the World mission and validation of data. Meteorological Organization (WMO) Since October 1994, in the frame- at the Main Geophysical Observa- work of the Baseline Surface Radi- tory in St. Petersburg. ation Network (BSRN), the MOL-RAO Through the DWD station at Required resources has collected data on short- and long- Lindenberg and the Ny Ålesund and Ground-measured and satellite-de- wave radiation in the upper atmos- Neumayer stations operated by the rived radiation data are of key import- phere, with a high temporal resolution Alfred Wegener Institute, Helmholtz ance for understanding the causes of and low measurement uncertainty Centre for Polar and Marine Research climate change. (≤ 2%). (AWI), Germany makes an important To this end, it is necessary to The worldwide comparability of contribution to the BSRN, which was maintain the ground-based reference German radiation data continues to established in the framework of the stations that already have long time be ensured by the calibration of World Climate Research Programme series of complex data sets, including measurement devices at the National (WCRP) and is now the reference radiation measurements. In future, Radiation Centre at the MOL-RAO. radiation network for GCOS. The data their operations should be extended The spatial coverage of all com- obtained are also forwarded to the to include the collection of spectral ponents of the radiation balance has World Radiation Monitoring Center radiation data. recently been consolidated by inten- (WRMC) hosted by the AWI in Bremen In addition, it will be important to sive use and processing of satellite (see Chapter 5.3). redress the current shortfall in profes- data made available by the Satellite The high-quality radiation data sional capacity for analysis of satel- Application Facility on Climate Moni- sets derived from satellite data in the lite data, ground-measured data and toring (CM SAF). framework of the CM SAF are also combined data sets. Part of this prob- highly significant for further research lem is the inadequate basic funding to verify climate change, particularly for universities, which undermines because of their comprehensive their capacity for sustainable coverage. research.

http://www.dwd.de

25 2.6 Sunshine duration

Sunshine duration is one of the main indicators for describing the climate for the purposes of different areas of application. In particular, it is an approximate indicator of radiation, for which only few long time series exist but which is of increasing importance in the context of the use of renewable energies.

Climate trends The measurements from the area- covering network were interpolated from 1951 onward on a regular grid, which allowed the computation of area average series. These enable the identification of climatological trends, and this largely irrespective of any inconsistency that might exist in the time series of single stations. The annual average of sunshine duration in Germany shows considerable variation from year to year, but so far there is no significant long- term trend to be seen.

Measurements in Germany The Deutscher Wetterdienst (DWD) operates a monitoring network of weather and climate stations, of which about 500 currently measure sunshine duration. This dense network has been in place for about 60 years. Going back to before that time, there exist only single time series which often contain inconsistencies due to differences in measurement methods and observation programmes. Between 1995 and 2005, in the context of the general automation of the networks, most of the stations were changed from Campbell-Stokes instruments based on the magnifying glass effect to automatic measurement equipment. As opposed to conventional are now available digitally, in real observations, which were analysed time and with high temporal reso- visually and only provided hourly lution. The different measurement values at large time delays and partly and analysis methods, however, with large uncertainties, the data have partly resulted in considerable from automated weather stations inconsistencies in the time series.

26 2 Atmospheric observations Near surface Annual mean sunshine duration in Germany for the period 1951–2011

s Positive (yellow) and negative (grey) deviations from the long-term mean (1961–1990) of annual sunshine duration for Germany

Legal framework International context The Law on the Deutscher Wetter- The synoptic reports (including sun- dienst (§ 4) gives the DWD responsi- shine duration data) from 180 sta- bility for short- and long-term regis- tions are distributed worldwide on a tration, monitoring and evaluation of routine basis. For a selected number meteorological processes as well as of these stations, quality-checked the structure and composition of the monthly climatological information atmosphere, and for the operation of is made available in the form of the required measurement and CLIMAT reports. The stations at Frank- observing systems. furt, Hamburg, Hohenpeissenberg and Lindenberg are part of the GCOS Surface Network (GSN).

Required resources The operation of the existing measuring stations can generally be considered as secured.

http://www.dwd.de

27 2.7 Temperature, wind and water vapour in the atmosphere

The layer of the atmosphere relevant for weather and climate extends to an altitude of more than 30 km. Over this range, temperature, wind, water vapour and pressure vary greatly and may be subject to abrupt changes over the time. Vertically resolved measurements of these parameters throughout this altitude range are essential not only for short-term weather forecasting, but also for observing the long-term development of the climate.

Legal framework sphere (at 100 hPa) rely on balloon The Law on the Deutscher Wetter- soundings only and reveal a signifi- dienst (§ 4) gives the DWD responsi- cant cooling of 0.5 K per decade (not bility for short- and long-term regis- shown) as opposed to the clearly tration, monitoring and evaluation of increasing trend in the troposphere, meteorological processes as well as where the mean temperature trend the structure and composition of the shows a warming of roughly 0.1 K atmosphere, and for the operation per decade. Measurements in Germany of the required measurement and Historical trends in tropospheric Vertical profiles of temperature, observing systems. Within this con- water vapour are impacted by large wind and water vapour are meas- text DWD supports numerous meas- uncertainties and only limited state- ured using radiosondes in Germany urement programmes for long-term ments about temporal variations at 14 stations. Nine of these stations climate observations, defines climate can be derived. Better estimates of are operational radiosonde sites reference sites, and assures the con- changes in tropospheric water vapour managed by the DWD; the other five tinuity of long-term data series. are expected with the implementa- are run in co-operation with the Bun- tion of GUAN and, in particular, of deswehr. The standard observational GRUAN, and with ongoing improve- programme of the DWD requires two ments in measurement technology. radiosonde launches per day. Only Long-term trends in stratospheric at the MOL-RAO, four radiosondes water vapour over several decades are launched each day operationally. Climate trends have been measured at only one Other sites may increase their sound- Temperature trends in the tropo- station in the world. The observa- ing frequency to four soundings per sphere and in particular in the strato- tions, which began at the Meteoro- day if needed during special weather sphere are of great importance for logical Observatory Lindenberg – conditions. the long-term understanding of Richard Assmann Observatory MOL-RAO is the only station in atmospheric processes. The graph (MOL-RAO) over six years ago, form Germany belonging to the GCOS on page 29 shows the time series for another anchor for estimations of Upper-Air Network (GUAN). It is also temperature at 850 hPa (including trends in stratospheric water vapour. the Lead Centre for the GCOS Refer- the data from kite ascents during the ence Upper-Air Network (GRUAN) first half of the 20th century). The red and the only GRUAN site in Germany. line indicates monthly mean values, Measurements in these networks the green curve a 12-month running strive for best possible homogeneity mean, and the blue line a simple lin- and continuity. As part of GRUAN, ear trend. Data for the lower strato- traceability to international standards

28 2 Atmospheric observations Free atmosphere Air temperature deviation from the long-term average at 850 hPa

International context with other GRUAN and GUAN sta- The scientific investigations of tem- tions. Data are shared through a perature and water vapour at MOL- number of different data centres and RAO are conducted in close co-oper- are processed and analysed in close ation with the international scientific scientific partnerships. These obser- community. The observatory plays a vations are the basis of recommen- leading role in observation tech- dations to decision-makers in policy niques, both internationally and in and administration at national and projects conducted in co-operation international level.

and a vertically resolved quantification of the uncertainty of measurements are of great importance. Required resources Changes in stratospheric water Long-term climate observations are vapour have large impacts on the currently threatened by austerity surface climate. Regular measure- measures. The value of climate time ments within the altitude range series is strongly susceptible to inter- from 10 km to 25 km take place ruption for which reason financial only at the MOL-RAO. continuity of the observation pro- In addition, vertical profiles of grammes is required. Reduced fund- water vapour are measured using ing particularly impacts observations a LIDAR, which under favourable of the free atmosphere through in- meteorological conditions may situ soundings, which so far are the provide data on the variability of only technology for climate reference water vapour at different altitudes data. These observations must be with high temporal resolution. continued without interruption and Vertically resolved observa- with sufficient overlap when system tions of temperature at Lindenberg changes occur, requiring continuous started as early as 1905; however, resource allocations. only within the last ten years have DWD observatory measurements of atmospheric DWD upper-air station humidity reached a level of quality BW geoinformation site sufficient for studying long-term trends in water vapour. s Upper-air stations in Germany http://www.dwd.de

29 2.8 Clouds

Clouds are essential for the energy and water balance of the atmosphere and therefore have a significant impact on weather and climate. Classical visual observations of clouds have been carried out at many locations, in some cases for more than 100 years. However, neither can small-scale spatial structures be captured, nor can the microphysical properties of clouds be inferred, which is why space-borne and ground-based remote sensing systems for cloud observation are gaining in importance.

Climate trends Only continuous monitoring over extended periods of time allows conclusions on climate change. Since these changes can be very small, the homogenisation of time series is very important, whereby changing methods of observation and measurement instruments must be considered. At the DWD’s climate reference stations, visual observations are International context Measurements in Germany performed at the same time as ceilo- Germany makes the largest contri- Visual observations are operationally meter measurements with the aim of bution to all European satellite pro- performed at 81 weather stations of producing consistent data sets. For grammes of ESA, EUMETSAT and the DWD and at 35 stations of the the homogenisation of measurement other EU-relevant climate monitor- Geophysical Service of the Bundes- data from satellites the products are ing activities. Processing of satel- wehr, several of which operate reprocessed within the CM SAF. lite data for the purposes of climate round the clock. monitoring is done at EUMETSAT Observables include cloud type, through the CM SAF. The World Data cloud cover and cloud base. The Legal framework Center for Remote Sensing of the time series go back to the 1940s, at The Law on the Deutscher Wetter- Atmosphere (WDC-RSAT, see Chap- some stations even to the 19th and dienst (§ 4) gives the DWD responsi- ter 5.5) is located at the German 18th centuries. For precise deter- bility for Aerospace Center (DLR), from where mination of the cloud base, laser n short- and long-term registration, the data are available to the scien- ceilometers have been used since monitoring and evaluation of tific community. the 1990s. meteorological processes and the To establish new satellite-borne Widespread observation of clouds structure and composition of the and ground-based observation from space began about 50 years ago. atmosphere, methods with active instruments Co-ordinated by Germany, Eumet- n for the operation of the required (radar and lidar), Germany participates sat’s Satellite Application Facility on measurement and observing in numerous European research pro- Climate Monitoring (CM SAF) is systems as well as grammes such as Cloudnet, ACTRIS, committed to exploiting the meas- n for the provision, storage and HD(CP)2 and EarthCARE. In addition, urements made by various passive documentation of meteorological Germany is represented on numer- instruments on geostationary and data and products. ous committees of the WMO. polar-orbiting satellites (e.g. Meteo- For the fulfilment of its duties, the sat, Metop) for essential climate DWD is engaged in scientific research variables, such as cloud parameters, in the field of meteorology and surface albedo, radiation fluxes and related sciences and contributes to temperature and humidity profiles. the development of corresponding Important cloud parameters, which standards and norms. have been determined operationally

30 2 Atmospheric observations Free atmosphere Mean monthly high cloud cover

Mean monthly low cloud cover

s The time series is derived from the measurements made with the 35-GHz radar at Lindenberg as compared with visual observations (synop) and simulations of the The DWD’s Lindenberg Meteoro- three weather forecasting models of the DWD, logical Observatory – Richard COSMO-EU, COSMO-DE and GME, for high Assmann Observatory (MOL-RAO) cloud cover (cloud base > 6 km) and low cloud has been continuously measuring cover (< 2 km). the fine structure of clouds with a 35 GHz radar since 2004. Due to the low attenuation of electromagnetic signals at this wavelength in both Required resources cloud-free and cloudy atmospheric In the future, visual observations conditions, the radar is able – in will only be made at DWD reference contrast to optical instruments – to stations, selected locations of the detect multi-layered clouds in their Geophysical Service of the Bundes- full vertical extent and to detect wehr and at airports. Ground-based structures (particles) above optically and satellite-based measurement thick clouds. methods can not only fill the gap, By comparing model-simulated but can provide data on macro- and cloud distributions and properties microphysical cloud properties, with observations important in- which visual observations would sights can be obtained to improve never be able to provide. In addition Visual observations cloud parameterisation in weather to investments in new systems, the Automatic weather observations forecast and climate models. development of appropriate retrieval methods, quality assurance over long time periods and the analysis since 2004, are: cloud cover, cloud and homogenisation of data require type, cloud optical thickness, cloud additional human resources. phase and cloud top. Continuous quality control is achieved by means of evaluation of the data against ground-based in situ and indirect http://www.dwd.de http://cmsaf.eu measurements.

31 2.9 Carbon dioxide

Greenhouse gases produced by humans are the most important cause of global warming. Apart from water vapour, carbon dioxide (CO2) is the most important climate-forcing gas, due to its high concentrations in the atmosphere. Since the start of industrialisation around

1750, global concentrations of atmospheric CO2 have risen by 40%. In contrast, over the previous 10,000 years, CO2 concentrations were nearly constant. The current rate of increase of atmospheric CO2 is about 100 times faster than at any time in the past.

Climate trends of existing CO2 concentrations are Long CO2 time series are a reliable needed. Article 192 Par. 1 of the Treaty measure of the global increase in on the Functioning of the European carbon dioxide. They provide con- Union provides the legal framework tinuous documentation of the effect for the new regulation 2011/0372 of fossil fuel burning on the atmos- (COD), which updates the EU system phere. Because these measurements in place since 2005 for monitoring are very precise, scientists are able greenhouse gas emissions. to distinguish the effect of fossil fuel burning from the annual fluctuation

of CO2 in the biosphere. This pro- Measurements in Germany the atmosphere. In Germany, these vides a reliable basis for the use of and abroad measurements are carried out in climate models to analyse long-term High-precision in situ measurements Bremen, Karlsruhe and Garmisch-

changes in the atmospheric burden of CO2 in the ambient air, like those Partenkirchen. The work is co-ord- of CO2 and calculate future scenarios. initiated by C. D. Keeling at Mauna inated by the Total Carbon Column Whereas in the 1950s the mean Loa, Hawaii, in 1958, have been Observing Network (TCCON) and

annual increase in atmospheric CO2 carried out at the mountain station contributes to the GAW programme was still only 0.55 ppm, differences on Schauinsland since 1972 and at of WMO. in mean annual values over the past the stations on Zugspitze and at Since 1996, Heidelberg University decade point to an increase of about Neuglobsow since 1981. They are has measured the climate-forcing gas

1.9 ppm per year. Thus, global CO2 complemented by flask sampling at CO2 in urban surroundings. It has been production has increased more than Hohenpeissenberg, which has been shown that long and high-precision threefold compared to the 1950s. carried out since 2006 in the frame- time series of measurements from work of the worldwide programme semi-polluted sites can be used suc- co-ordinated by the National Oceanic cessfully for independent verification and Atmospheric Administration’s of statistically based reports on Legal framework Earth System Research Laboratory regional greenhouse gas emissions, In the framework of the German con- (NOAA/ESRL). Data from GAW sta- for example those produced for the tribution to the international Global tions in Germany are retrievable from United Nations Framework Conven- Atmosphere Watch (GAW) pro- the World Data Centre for Green- tion on Climate Change (UNFCCC). gramme of the World Meteorological house Gases (WDCGG), based in In the framework of the German Organiziation (WMO), the Federal Tokyo. contribution to the GAW programme,

Environment Agency (UBA) is the Since 2004, measurements of CO2 Heidelberg University has taken CO2 partner agency responsible for the concentrations using solar absorption flask samples at the Neumayer GAW measurement of carbon dioxide. spectroscopy have been carried out Global station in the Antarctic since Germany has further statutory obli- at approximately 20 stations around 1994. TCCON measurements under gations in the context of national the world. This technique provides German lead management are con- emissions trading, for which precise data on total column concentration of ducted in Spitzbergen (Norway),

statistical emissions surveys and CO2, from the observation point on Białystok (Poland), Orléans (France) reliable and accurate time series the ground to the upper boundary of and on Ascension Island.

32 2 Atmospheric observations Atmosphere composition Trend in carbon dioxide (CO2) 1957–2011

Orange symbols: the three German GAW sites, Time series of CO2 measurements at the Neuglobsow, Schauinsland and Zugspitze, and German GAW stations Schauinsland and

Heidelberg University, where atmospheric CO2 Zugspitze, in comparison with the world’s

is measured in situ longest CO2 time series from Mauna Loa, Purple symbols: Bremen, Karlsruhe and Hawaii

Garmisch-Partenkirchen sites, where CO2 in the total atmospheric column is measured for the TCCON

International context Together with the Regional stations Schauinsland and Neuglobsow, the GAW Global station Zugspitze/Hohen- peissenberg makes the core German

contribution to CO2 data for GCOS. In the framework of the ‘D-A-CH’ co-operation between Germany, Austria and Switzerland, time series

Since 2003, the global distribution of CO2 measurements from the of atmospheric CO2 has also been mountain stations Zugspitze, Hohen- determined by satellite. Although less peissenberg, Hoher Sonnblick and accurate than ground-based measure- Jungfraujoch are analysed together Required resources ments, satellite data give a represen- to enhance the reliability and spatial CO2 measurements at the three GAW tative overview of the large-scale representation of the results. Data stations in Germany receive long- spatial distribution of CO2. A particular measurements are transmitted to term funding from the UBA. The sta- interest in this case is to determine the WDCGG on a regular basis. The tions are under-staffed. At present, natural CO2 emissions as well as measurements are based on the the cost of TCCON measurements is those caused by humans on a global GAW’s standard reference scale pro- only partly covered by institutional scale with the best possible spatial vided by the NOAA’s agencies in funding and these activities are and temporal resolution. This requires Boulder, Colorado, for CO2 measure- dependent on additional finance from satellite measurements highly sensi- ments. Quality assurance is reviewed third-party funded projects. Long- tive to changes in CO2 levels close to regularly by round-robin tests carried term funding is urgently required in ground, thus close to the emission out in the framework of the Carbo- order to ensure the continuity of sources. The first satellite instrument Europe project and WMO/GAW pro- operations. to fulfil these requirements is grammes. Total column measure- SCIAMACHY, aboard the European ments contribute to the international environmental satellite ENVISAT, effort co-ordinated by the TCCON. which was developed under German lead management.

http://www.dwd.de/gaw

33 2.10 Methane

Since the pre-industrial era, the presence of methane (CH4) in the atmosphere has increased by 270% as a result of human activity. Among long-lived greenhouse gases, CH4 makes the second largest contribution, after carbon dioxide, to global warming. Concentrations of methane in the earth’s atmosphere are higher today than at any time in the past 650,000 years. Although the rise slowed after 1990 and concentrations remained stable at a high level until 2005, climate models predict an accelerated increase in methane concentrations with increasing global warming. Since 2007, global networks and satellites have observed a renewed sharp rise in CH4.

Climate trends Long high-precision time series provide a reliable picture of methane concentrations, which are the overall result of interactions between sources Measurements in Germany Since 2004, measurements at and sinks. Although the sources of and abroad about 20 stations worldwide have

CH4 are known, trends in sources and In Germany, in situ measurements been using solar absorption spectros- their interaction with sinks cannot be of atmospheric methane have been copy and new kinds of instruments

fully explained. While CH4 continues carried out at the Schauinsland to measure CH4 concentrations in to show an upward trend, the rate mountain station since 1991 and at the near-infrared spectrum. This of increase in its concentrations has the stations on Zugspitze and at technique provides data on concen- steadily declined in the last two and a Neuglobsow since 1994. They are trations in the total column, from the half decades; the reasons for this, and complemented by flask sampling at observation point on the ground to the consequences for future global Hohenpeissenberg, which has been the upper boundary of the atmos- warming, are not yet sufficiently carried out since 2006 in the frame- phere. An average concentration in understood. Long and reliable time work of the global programme co- the troposphere can be derived from series are fundamental for efforts to ordinated by the National Oceanic this data. The work is co-ordinated improve our understanding of the and Atmospheric Administration’s by the Total Carbon Column Observing interaction of sources and sinks. Earth System Research Laboratory Network (TCCON). In Germany, (NOAA/ESRL). Data from GAW these measurements are carried out stations in Germany are retrievable in Bremen, Karlsruhe and Garmisch- Legal framework from the World Data Centre for Partenkirchen. In addition, since Within the Global Atmosphere Watch Greenhouse Gases (WDCGG), based 1995, long-term Fourier Transform (GAW) programme of the World in Tokyo. Infrared Spectroscopy (FTIR) meas- Meteorological Organization (WMO) – Since 1996, Heidelberg Univer- urements in the traditional mid-infra-

a component of GCOS that monitors sity has measured CH4 concentra- red spectrum have been carried out essential climate variables related tions in urban surroundings. It has on Zugspitze. These form part of the to atmospheric composition – the been shown that long and high- activities of the Network for the German Federal Environment Agency precision time series of measure- Detection of Atmospheric Compos- (UBA) is the partner responsible for ments from such locations can be ition Change (NDACC) and also measurement of methane. Article 192 used successfully for independent provide highly precise data on total Par. 1 of the Treaty on the Functioning verification of statistically based column concentrations of methane. of the European Union provides the reports on regional greenhouse gas The measurements contribute to the legal framework for the new regulation emissions, for example those GAW programme of WMO. 2011/0372(COD), which updates the produced for the United Nations In the framework of the German EU system for monitoring greenhouse Framework Convention on Climate GAW contribution, Heidelberg gas emissions. Change (UNFCCC). University has taken flask samples

34 2 Atmospheric observations Atmosphere composition Methane concentrations 1994–2011 (Schauinsland and Zugspitze)

Methane (CH4) time series measured at Schauinsland (green) and Zugspitze (orange)

stations. CH4 concentrations are higher at Schauinsland because this station is at a lower altitude; however, even here, the trend in the free troposphere is discernable.

International context spatial representation of the results. Together with the GAW Regional sta- Data measurements are transmitted tions Schauinsland and Neuglobsow, to the WDCGG on a regular basis. the GAW Global station Zugspitze/ The measurements are based on the Hohenpeissenberg makes the core GAW’s standard reference scale pro- German contribution to methane vided by the NOAA’s agencies in

data for GCOS. In the framework of Boulder, Colorado, for CH4 measure- the ‘D-A-CH’ co-operation between ments. Quality assurance is reviewed Germany, Austria and Switzerland, regularly by round-robin tests carried

time series of CH4 measurements out in the framework of the Carbo- from the mountain stations Zugspitze, Europe project and WMO/GAW. Total Hohenpeissenberg, Hoher Sonnblick column measurements contribute to and Jungfraujoch are analysed to- the international effort co-ordinated gether to enhance the reliability and by the TCCON.

Orange symbols: the three German GAW sites, Required resources Neuglobsow, Schauinsland and Zugspitze, and Methane measurements at the three

Heidelberg University, where CH4 is measured GAW stations in Germany receive in situ, i.e. in the ambient air long-term funding from the UBA. The Purple symbols: Bremen, Karlsruhe and stations are under-staffed. Atpresent, of CH4 at the GAW Global station Garmisch-Partenkirchen sites, where CH4 in the the cost of TCCON measurements is Neumayer in the Antarctic since total atmospheric column is measured for the only partly covered by institutional 1987. TCCON funding and these activities are de- TCCON measurements under pendent on additional finance from German lead management are third-party funded projects. Long- conducted in Spitzbergen (Norway), term funding is urgently required in Białystok (Poland), Orléans (France) order to ensure the continuity of and on Ascension Island. operations. Since 2003, the global distribution of atmospheric CH4 has also been determined by satellite. http://www.dwd.de/gaw

35 2.11 Other greenhouse gases

Even without its most important members, carbon dioxide

(CO2) and methane (CH4), the group of long-lived climate forcers (LLCFs) still makes a very large contribution to the greenhouse effect. The most important LLCFs are nitrous oxide (N2O), sulphur hexafluoride (SF6) and climate-relevant halogenated compounds. This group includes some extremely long-lived substances such as SF6 and NF3, with lifetimes of 3,200 years and approximately 640 years respectively, which will continue to affect the global climate for a very long time.

Climate trends out measurements of N2O, SF6 and Among long-lived greenhouse gases, hydrogen (H2) as well as climate-

N2O makes the third-largest contribu- relevant halogenated compounds. In tion to global warming. Its atmos- accordance with the EU’s obligations pheric abundance has increased only under the Kyoto Protocol, the pro- by 20% compared to pre-industrial posed EC regulation 2011/0372(COD) times (1750). However, at a time hori- of November 2011 revises the system

zon of 100 years, N2O has a global in place since 2005 for monitoring warming potential 300 times as large greenhouse gas emissions. Important

as that of CO2! About 40% of N2O objectives are to improve the moni- amounts emitted into the atmosphere toring and verification of emissions result from human activity. The re- by sources and removals by sinks. mainder comes from natural sources.

Atmospheric N2O levels show a slight north-south gradient, largely ex- Measurements in Germany Germany, these measurements are plained by the larger proportion of and abroad carried out in Bremen and Garmisch- land area in the northern hemisphere In Germany, in situ measurements Partenkirchen. The potential and

and the use of artificial fertilizers in of N2O, SF6 and the indirect green- limitations of this technique for meas- the mid-latitudes. Long high-preci- house gas H2 are carried out by the uring total column concentration of

sion series from both the northern Federal Environment Agency (UBA) N2O are currently being analysed. and southern hemispheres are a key at the GAW stations Schauinsland Since 1990, similar measure- requirement for improved under- and Zugspitze and by Heidelberg ments using solar absorption spec- standing of sources and forecasting University in an urban surrounding. troscopy have been carried out in of future trends. To do so, the in situ Data from GAW stations in spectral regions other than those time-series data must be measured Germany are retrievable from the used in the TCCON, which allows with a very high degree of accuracy World Data Centre for Greenhouse numerous other substances to be

(0.03%), which is close to the max- Gases (WDCGG), based in Tokyo. detected including SF6. These meas- imum technically achievable today. Since 2004, long-lived climate- urements are performed by the Net- relevant trace gases have been meas- work for the Detection of Atmospheric ured at about 20 stations around the Composition Change (NDACC) at Legal framework world using solar absorption spec- sites including the German NDACC As part of its official participation in troscopy. This technique provides station Zugspitze. the Global Atmosphere Watch (GAW) data on total column gas concentra- The long-term influence of water programme of the World Meteoro- tions, from the observation point on vapour, which is the most important logical Organization (WMO) – a compo- the ground to the upper boundary of greenhouse gas, on climate change nent of GCOS that monitors essential the atmosphere. The work is co-ordin- is being studied at the Zugspitze/ climate variables related to atmos- nated by the Total Carbon Column Schneefernerhaus site. On clear pheric composition – Germany carries Observing Network (TCCON). In nights, tropospheric water vapour

36 2 Atmospheric observations Atmosphere composition In situ concentrations of nitrous oxide: monthly mean values at Schauinsland and Zugspitze

Nitrous oxide (N2O) time series from the GAW Regional station Schauinsland (green) and Zugspitze Plattform at the GAW Global station Zugspitze/Hohenpeissenberg (purple) Orange symbols: the two German GAW stations Schauinsland and Zugspitze, and the urban surrounding site of Heidelberg Univer- International context

sity, where N2O, SF6 and H2 are measured Together with the GAW Regional sta- Purple symbols: TCCON sites at Bremen and tion Schauinsland, the GAW Global Garmisch-Partenkirchen and NDACC site station Zugspitze/Hohenpeissenberg

Zugspitze, where the total column of N2O is makes the core German contribution

measured. Water vapour vertical profiles up to to N2O and SF6 measurement for an altitude of 12 km (which currently is being GCOS. Data measurements are trans- extended to 30 km) are measured at Zugspitze mitted to the WDCGG on a regular on a long-term basis. basis. The measurements are based on the GAW’s standard reference scale provided by the NOAA’s agen-

cies in Boulder, Colorado, for N2O and Required resources SF6 measurement, and on the refer- At present, the costs of TCCON and ence scale for H2 maintained by the NDACC measurements are only Max Planck Institute in Jena. Quality partly covered by institutional fund- assurance is reviewed regularly by ing and these activities are depend- round-robin tests carried out in the profiles up to an altitude of 12 km ent on additional finance from third- framework of the Carbo-Europe pro- have been measured at this site party funded projects. Long-term ject and WMO. Total column measure- since 2007 using infrared (IR) funding is urgently required in order ments contribute to the international differential absorption lidar (DIAL). to ensure the continuity of operations. efforts co-ordinated by TCCON and Since 1996, Heidelberg Univer- Until now, Germany has not collected NDACC. The major importance of sity has taken measurements of the continuous time-series data on halo- these measurements is that they can greenhouse gases N2O and SF6 and genated greenhouse gases in the be used to validate satellite instru- the indirect greenhouse gas H2 in ambient air (in situ). The UBA assumed ments, which have similar viewing urban surroundings. It has been responsibility for this activity in 1998. geometry and also measure the total shown that long and high-precision It has the requisite measurement column. Airborne measurement cam- time series of measurements from technology; however funding is still paigns were conducted to adjust the such locations can be used success- lacking for a scientist and a technician TCCON total column measurements fully for independent verification of to perform the measurements at the to existing in situ measurements. statistically based reports on regional GAW Global station Zugspitze/ Both TCCON and NDAAC measure- greenhouse gas emissions, for ex- Hohenpeissenberg. ments are accepted by GAW/WMO. ample those produced for the United Nations Framework Convention on Climate Change (UNFCCC). http://www.dwd.de/gaw

37 2.12 Ozone

The colourless and poisonous gas ozone (O3) is one of the most important trace gases in the atmosphere. Most of this gas (more than 90%) is found in atmospheric layers above 10 km (stratosphere). The stratospheric ozone layer protects the earth from harmful ultraviolet radiation from the sun. In lower atmospheric layers, the gas is present as ‘background ozone’, as a result of hemispheric transport and natural ozone production, which makes it a focus of attention in this context. Additional ozone is created in strong sunshine by chemical processes from precursor pollutants. Furthermore, ozone is a greenhouse gas and thus contributes to global warming of the earth’s atmosphere.

Legal framework across national frontiers. Data from Monitoring of air quality – including the GAW’s Global station Zugspitze/ ground-level ozone – is carried out in Hohenpeissenberg and Regional sta- Germany according to EU air quality tions Schauinsland and Neuglobsow regulations, which are incorporated contribute to the GAW programme. into German law through a Regula- tion Pertaining to the Federal Immis- sion Control Act (39. BlmSchV). This Measurements in Germany regulation sets ozone target values Measurements of ground level for the protection of human health ozone concentrations in Germany and vegetation. Information and alert were initiated in the mid-1970s. By thresholds are established in order to 1990, there were already 194 ozone counter the risks to human health measurement stations, distributed associated with short-term exposure over the whole of Germany. Cur- to high ozone concentrations. rently (August 2012), ozone concentrations are measured at 270 locations, in towns and conurbations and in rural areas. In accordance International context with the Federal Immission Control All ozone data collected in Germany Act, the German Länder are respon- UBA measurement stations Rural area in the framework of European air sible for monitoring air quality, and Urban area Urban traffic area quality guidelines are transmitted to measurement networks have been the European air quality database established for this purpose. In order The ozone measurement AirBase, established and managed by to check international activities and programme at the European Environment Agency compliance with clean air strategies Hohenpeissenberg Observatory (EEA). From there, the data can be the Federal Environment Agency Ozone measurements on a routine retrieved for use all over Europe in (UBA) operates its own measure- basis were started at the Hohenpeis- research, statistical analysis and by ment network, consisting of seven senberg Meteorological Observatory projects, and as a source of real-time measurement stations that meas- (MOHp) in 1966/67. Ozone sampling data. ure pollutant concentrations in air using Brewer-Mast ozone sondes The UBA measurement stations masses transported over long dis- coupled to radiosondes was initially are also part of the European Moni- tances and across national frontiers. carried out on a weekly basis. Since toring and Evaluation Programme These stations are located as far 1978, samples have been taken twice (EMEP) for the investigation of pol- away as possible from local sources a week in summer and three times a lutant concentrations in air masses of air pollution. week in winter. The sampling ensem- transported over long distances and ble is transported by a balloon to an

38 2 Atmospheric observations Atmosphere composition Trends in annual average ozone concentrations 1990 to 2011

s Source: UBA, incorporating data from measurement networks operated by the Länder and the UBA

Climate trends oxide emissions. As nitrogen oxide Since 1990, there have been notable is predominantly emitted in the form reductions both in the maximum of nitrogen monoxide (NO), the level of ozone concentrations and reduction in NO emissions leads to a the frequency of occurrence of very weakening of the titration effect, by high levels of ozone. Emission reduc- which ozone is broken down and tion measures introduced in the converted to nitrogen dioxide in an altitude of more than 30 km and 1990s to combat ‘summer smog’ oxidation reaction with locally emit- provides continuous measurements have proved to be effective. In com- ted NO. This increases the lifetime of of ozone partial pressure during the parison with levels in 1990, emis- ozone. The rise in average annual ascent, including in the stratospheric sions of ozone precursors – nitrogen ozone levels in cities is the result of ozone layer. oxide and unstable organic com- a falling number of low ozone values, In 1967, measurements of total pounds, excluding methane – have together with a rise in the number of ozone concentrations were initiated declined by 54% and 66% respect- medium ozone values. The increase using Dobson spectrometers. The ively. However, target levels for the in average annual values in rural Dobson and sonde technologies are protection of human health continue areas is primarily explained by the the foundation of the observatory’s to be exceeded. In contrast to max- increasing proportion of the ozone long and homogenous ozone data imum levels, annual average ozone burden arising from northern hemi- series. The measurement programme concentrations have risen in the sphere transport. was expanded through the incorpor- same period. Measurement stations ation of a Brewer spectrophotometer in urban locations – that is in typical and a laser radar (lidar) device. Thanks residential areas – and in urban traffic to the maintenance from the start of areas provide evidence of a highly strict quality controls, the ozone data significant rise in average ozone con- set at Hohenpeissenberg is unique in centrations from 1990 to 2011, while the world. Since 1999, Hohenpeissen- ozone levels have also risen signifi- berg has hosted the European Dobson cantly in rural locations (see graph). Required resources Calibration Center. During the observation period, a shift Due to the legal obligation to monitor The Hohenpeissenberg ozone from low to medium concentrations ground level ozone concentrations measurements contribute to the has taken place. The cause of this in Germany, long-term continuity of Global Atmosphere Watch (GAW) trend is the reduction in nitrogen these programmes is assured. programme of the World Meteoro- logical Organization (WMO).

http://www.umweltbundesamt.de/luft/schadstoffe/ozon.htm http://www.dwd.de/ozon

39 2.13 Aerosols

Aerosols have a predominantly cooling effect on the atmosphere. The exception is black carbon (BC, also referred to as soot), which belongs to the short-lived climate forcers. When it lies on snow or ice it reduces the albedo down to a few per cent and causes a strong warming effect. What is more, the impacts of aerosols on the global climate are not as well explored as those of climate-forcing gases, with the aerosol time series being much shorter than those of climate-forcing gases.

Climate trends Similar to the particle mass, there is a great difference in levels of soot measured between urban and rural areas. One well-known source of soot is traffic (especially from diesel vehicles), which is the reason for the high values at sites close to traffic, with mean values around to 2-4 µg/m3. At rural sites, the figures are considerably lower, around 0.5 µg/m3, and in the summer at mountain stations they are even lower. The lowest value is Measurements in Germany observed at the Zugspitze, where soot In addition to investigations into size mass concentrations drop to 0.02 µg/ distributions and aerosol chemistry, Legal framework m3. The level of soot at a specific black carbon has been measured Directive 2008/50/EC of the Euro- measuring site, just as the number of continuously in Germany at 19 dif- pean Parliament and the Council of ultrafine particles, functions as a ferent sites within the framework of 21 May 2008 on ambient air quality sensitive indicator of the influence of the German Ultrafine Aerosol Net- and cleaner air for Europe has super- local burning sources. Analogous to work (GUAN) since October 2008. seded the previous council directive the particle mass, a strong annual The GUAN network was established 96/62/EC of 27 September 1996 on variation in concentration of soot on behalf of the Federal Environ- ambient air quality assessment and can be observed. In flat country, the ment Agency (UBA) by the Leibniz management and three subsidiary highest values (peaking at 10 µg/m3) Institute for Tropospheric Research directives (1999/30/EC, 2000/69/EC occur in winter whereas in mountain- and 2002/3/EC), in which threshold ous country they occur in summer.

values for SO2, NO2, NOx and PM10 This is caused by the annual variation and further gaseous air pollutants in the height of the mixing layer. were given. Thus, in the entire EU, During the summer, the mixing layer up to now no directives exist that set is considerably higher, up to more than threshold values for short-lived cli- 3.5 km. This results in good mixing of mate-forcing aerosols such as black gases and particles, resulting in carbon. Threshold values exist only similar summertime levels of around for ultrafine aerosols and PM10, and 0.5 µg/m3 at all rural measurement for the latter so far no definite con- sites. During the winter, layers are nection with temperature warming is inverted and this reduces dispersion, known (Kuttler, 2011). allowing concentrations to increase in flat country. But then, the inverted mixing layer is often lower than the mountain measuring stations, for which reason they report considerably lower concentrations (Ufoplan, 2011).

40 2 Atmospheric observations Atmosphere composition Moving weekly averages of the aerosol optical measurement of soot

s Moving weekly averages of the aerosol optical measurement of soot, measured as mass concentration in µg/m3 Source: Ufoplan, 2011

in the context of a project to deter- to establish the extent of the trans- International context mine the typical exposure of the portation of particles from volcanoes The GUAN network is part of the population to fine and ultrafine aero- and the Sahara. continuing European measurement sols. Elemental carbon and organic programmes and projects such as In Germany, continuous nephel- carbon have been measured by the EMEP, EUSAAR and ACTRIS. In ometer measurements of forward and UBA since June 2011 at the GAW accordance with normal practice, backward scattering from aerosols at Regional stations Schauinsland GUAN data can be retrieved from three wavelengths are taken at both and Neuglobsow as well as at its the EBAS database of the Norwegian sites of the Zugspitze/Hohenpeissen- own measurement sites Schmücke Institute for Air Research (NILU). berg GAW Global station. Those data and Neuglobsow. also serve for determining single- PM10 concentrations in ambient scattering albedo, which can be used air are measured in Germany at the three official GAW measurement sites at Neuglobsow, Schauinsland and Zugspitze and at all stations of Required resources the UBA’s air measurement network Funding of the GUAN network is (Westerland, Zingst, Waldhof and secured from 2008 until the end of Schmücke). PM10 is also measured 2013 by the Federal Ministry for the Locations of the 19 stations of the German in the air-quality monitoring net- Environment, Nature Conservation Ultrafine Aerosol Network (GUAN). works of the German Länder at and Nuclear Safety (BMU). Funding The colours characterise site environment: more than 330 stations, which are of current nephelometer measure- red: traffic oriented, orange: urban context, mostly situated in more densely ments is secured permanently by the green: rural context and light blue: alpine populated or urban areas. UBA and the Deutscher Wetterdienst area. (DWD), the funding of PM10 by the German Länder.

http://wiki.tropos.de/index.php/GUAN

41 2.14 Pollen

About 20 million people in Germany suffer from pollen allergies – this is about one quarter of Germany’s total population (Ring et al., 2010). The tendency is increasing. Pollen production and release by plants are decisively influenced by the weather with all its complex characteristics. Continuous and long-term pollen counts can document changes in the start and total length of the pollen season and identify increasing or decreasing pollen concentrations or the occurrence of new invasive pollen species at an early stage. Potential changes are important indicators for the impact of climate change on main allergy triggers.

Climate trends plant in Germany will cause the Trends caused by climate change are concentrations of its pollen in the apparent already in all regions of atmosphere to rise as well. All in all, Germany (Kaminski and Glod, 2011). allergies will increase continuously; Taking grass pollen in southern therefore surveillance of pollen Germany as an example, the pollen occurrence is becoming more and season starts earlier and lasts longer more important. (see graph). In north-eastern and southern Germany, the birch pollen concentration is increasing signifi- Measurements in Germany cantly. The Pollen Information Service The largest changes to the start Foundation (PID) was established of the pollen season and to pollen in 1983. The PID’s pollen network concentrations have occurred in covers at present about 45 stations southern and north-eastern Germany. for continuous sampling of pollen In all regions under consideration, in ambient air. Most of the stations it is evident that tree pollen allergies have been run since the mid-1980s. are becoming increasingly important, Germany’s reunification in 1990 Operational pollen station of PID (seasonal analysis) compared to plant pollen allergies, enabled the pollen network of the PID reference station (yearly pollen analysis) due to a greater increase in tree pol- Federal Republic of Germany to be s len. The main reasons for this are expanded to the new Länder. Dur- Pollen network of the Pollen Information

climatic changes (rise in CO2 concen- ing the pollen season from spring Service Foundation (PID) trations and in temperature) as well to autumn, pollen emission meas- The DWD runs a reference station at the as changes in land use (destruction urements are performed by trained Centre for Human Biometeorological Research of grass surfaces and increased culti- personnel. There are ten reference (ZMMF) in Freiburg, where the pollen forecasts vation of trees). stations where pollen counts are are issued. New types of pollen such as recorded throughout the whole olive and wall pellitory will be more year. All stations are equipped with ing, in close co-operation with the significant in the future. The highly Burkard traps and the operating PID, pollen forecasts for Germany as allergenic pollen of ragweed reaches procedures for the preparation and part of its statutory task to provide Germany predominantly by long- evaluation of the samples are services for the protection of life and distance transport from southern uniform for all stations. property. The forecasts consider the France and Hungary (Kaminski et al., Since 1986, the Deutscher Wet- seven most allergenic pollen taxa: 2010). But the evident spread of this terdienst (DWD) has been publish- hazel, alder, birch, grasses, rye, mug-

42 2 Atmospheric observations Atmosphere composition Start and end of the grass pollen season in southern Germany 1988–2010

s Compared to 1988, the grass pollen season in Legal framework southern Germany now starts earlier and ends The Law on the Deutscher Wetter- later. Its total length has extended by 24 days. dienst (§ 4) gives the DWD responsibility for the provision of meteorological services for the general public or individual customers and users in the area of public health. The PID, based in Berlin, operates the pollen network and provides the DWD (based on a bilateral agreement) with the data needed to issue and disseminate pollen forecasts for the public.

wort and ragweed. Due to the aller- International context Required resources genic relevance of ash pollen, a fore- As pollen dispersal does not respect Apart from the DWD measurement cast will soon be added for this plant national borders, international data station in Freiburg all other stations as well. exchange is required. For this pur- are placed at medical facilities. Pollen Depending on the weather in pose, the European Aeroallergen counters receive an expense allow- autumn and winter, pollen forecasts Network (EAN) database was estab- ance from PID for their work. The mostly start with the first occurrence lished in 1988, with 152 users from fail-safe operation of these stations of hazel pollen at the end of January 48 countries including Germany depends on external boundary or beginning of February, sometimes connected to it. It includes pollen conditions, which are difficult to even as early as December. They are count data of 170 pollen types from control. issued until about the middle of Octo- 557 stations across Europe, which Due to the high significance of ber when ragweed pollen release has are available free of charge for pollen measurements, a basic level ended. In 2007, DWD introduced a research purposes. The database of finance for the pollen network newsletter for information on pollen includes valuable information about would be useful to guarantee con- release. The number of copies dis- the spatial and temporal development tinuous measurement of high quality patched illustrates the importance of pollen concentrations in the air in the future. attached by the public to this infor- over Europe. In addition, German As pollen counting is extremely mation. Up to 2011, the numbers pollen data are stored in the PID’s time-consuming, efforts are being dispatched increased steadily to own database. made to automate pollen measure- over 10,000 per day. ment in order to save resources.

http://www.dwd.de/pollenflug http://www.pollenstiftung.de/

43 3.1 Ocean temperature

Sea surface temperature provides an integral measure of meteorological forcing and the resulting changes in the climate and ecology of the North Sea region. For more than 40 years, the Federal Maritime and Hydrographic Agency (BSH) has been performing weekly analyses of sea surface temperature. The growing data archive documents the dynamic development of this key oceanographic variable.

4˚WLegal framework0˚ 4˚E 8˚E 12˚E 86 24 11 14 16 10 2 41Under10 3 the Maritime1 1 4 7Shipping2 2 (Fed-2 1 1 4 5 9 20 15 16 31 11 1 1 2 1 8 3 1 1 2 13 1 23 11 3 19 4 1 1 1 eral Competences)1 10 3 1 Act (SeeAufgG,3 1 1 2 15 4 3 4 1 2 1 5 3 13 7 1 1 1 1 1 1 2 5 8 1 § 1), the BSH is responsible193 for 1 3 6 12 3 2 1 1 1 2 1 5 15 7 3 1 3 2 2 13 2 1 2 9 7 1 1 1 oceanographic2 10 10 3 5 3 surveys,1 6 1 3monitoring1 1 1 1 6 1 101 2 3 1 2 4 1 1 of12 changes5 15 11 1 in6 11the6 marine2 1 4 3 environ-2 1 2 13 1 941 2021 51 1 6 2 1 7 8 3 6 2 5 1 5 9 2 1 1 2 15 2 1838 ment and provision of hydrographic 32 3 2 16 1 1 4 3 6 14 48 3 1 3 1 7 4 2 1 4 3 3 3 6 7 4 2264567 Climate trends 1 7 4 2 1 2 25 2 5 4services.11 14 3 1 The5 publication4 2 2 5 1 of5 sea3 2 4 10 11 4 100 The behaviour 60˚Nof the non-linear2 1 1 2 5cli-6 3 2surface3 2 temperature7 1 1 3 charts1 2 is2 one13 17 of 2 5 2 60˚N mate system is, amongst5 3 other3 5 5 1 2 1 6the1 6services 7provided2 5 4 3 by4 3 the2 BSH,17 18 3 1 1 5 4 1 3 7 6 2 11 9 3 1 1 5 2 1 2 5 7 5 2 6 2 5 4 2 5 4 3 4 6 3 4 9 16 2 things, marked by abrupt8 1 7tempera-8 13 5 5 3 3 4drawing4 4 4 8 on6 3the3 results5 5 3 12 of2 its4 survey9 5 4 1 3 6 9 1 1566 ture changes at all time1 7scales.2 1 3 The5 5 9 5 4and11 9 monitoring2 10 5 3activities.4 13 3 6 2 3 2 3 11 6 2 3 10 1 3 2 1 5 2 5 12 4 4 9 1 3 1 6 10 6 5 5 1 4 1 1 4 2 7 10 1 time series of annual mean5 3 1 3tempera-3 2 3 10 11 9 4 3 5 9 2 3 9 2 2 1 1 3 1 8 13 ture in the North Sea 11shows1 1 2 a 6tem-3 1 2 1 5 6 7 5 6 5 10 9 3 9 3 7 1 3 2 2 5 2 1 3 7 12 2 3 perature climate which4 is7 13character-14 11 6 8 7 7 3 Measurements6 2 2 4 3 3 1 7 13 11in10 Germany3 8 5 6 10 10 3 3 7 4 In15 addition,1 33 regular monitoring1 1 2 6 6 8 1 3 6 1 2 7 2 5 1 5 6 11 3 36 28 5 1 2 3 6 7 1 1 1 1 1 ised by abrupt regime12 changes3 on 6 13 Worldwide,4 2 1 3 1 9 sea2 2 surface2 3 7 2 tempera-7 1 7 3 2 3 3 cruises3 1 5 are undertaken in the North3 653 12 3 2 4 11 5 6 5 1 1 4 5 8 1 2 1 4 5 5 3 6 4 9 4 5 2 1 2 1 1 3 4 1 intra- to inter-decadal time scales. ture (SST) is the most closely1132 moni- and Baltic Seas by the BSH itself or A linear trend of +0.3 K per1 decade 14 2 2 tored3 9 5 of4 5all5 oceanographic4 1 4 4 2 6vari-5 3 7 1 4 other6 3 16 agencies10 7 1 1 on its behalf.4 4 Ocean3 3 2 2 5 5 7 7 23 35 11 7 4 68 5 1 6 3 5 5 9 4 5 3 2 4 5 8 8 7 14 11 10 7 10 8 2 1 5 10 6 9 9 11 14 5 5 17 4 suggests a gradual increase in 1 1 6 ables.9 15 8 7It 15is 4also2 7 a5 very4 2 important8 2 1 2 5 2 1 2 temperature5 2 10 7 3 9 2measurement12 10 10 28 26 10 9is 4part13 14 of30 35 21 19 13 11 3 3 5 3 1 5 3 6 1 1 1 1 2 2 3 4 1 3 2 2 9 24 11 10 3 3 5 5 22 12 6 5 14 7 temperature, but this is not what climate variable172 that, together with the standard programme during 2 10 4 2 3 2 16 8 2 2 3 3 1 3 3 6 3 2 1 6 1 4 1 4 2 2 3 19 52 23 4 2 19 occurred. Interestingly, synchronous near-surface10 8 4 2 1 5 air2 temperature,5 3 5 2 1 5 is1 1 1 1 these5 1 cruises.7 1 4 The1 2 measurements1 2 9 13 41 7 1 3 12 1 504 abrupt displacements of winter used4 6 5 to3 describe3 2 4 1 5 global5 2 2 tempera-2 2 2 are1 obtained3 1 4 6 7through4 3 7 1 thermosalino-5 13 10 7 4 9 3 2 5 2 2 7 13 14 6 6 4 6 3 2 4 4 2 8 5 3 2 10 5 7 3 5 5 8 20 21 1 15 4 1 atmospheric circulation in the north- ture trends over2501 the 116past 160 years. graphs, conductivity, temperature 2 1 1 1 1 2 8 3 4 1 1 3 4 1 5 3 3 1 3 25 14 5 1 2 3 10 5 1 ern hemisphere have 2been reported 6 11 10 1 Historical2 1 2 1 ocean3 temperature2 2 1 2 2 3 10and13 depth1 51 15 1sampling4 5 8 13 21and12 towed1 2 2 9 5 6 (Watanabe and56˚N Nitta, 1999). In par- 2 3 19time1 5 series3 exist,1 for2 2example,5 4 1 for3 17 15 17 oceanographic9 9 2 3 5 10 5 5 systems12 11 2 11 and1 provide 10 12 6 8 5 3 56˚N ticular, regime shifts in ocean tem- 3 6 4 the5 German3 1 1 2 2Bight1 1 and2 4 3the2 western2 6 2 6 3 13a quasi-synoptic2 2 2 6 7 3 18 13view6 15 of4 spatial1 and 4 7 10 16 7 4 6 13 8 6 1 4 2 2 5 4 6 4 3 1 4 2 13 8 3 7 6 6 6 3 8 7 33 11 10 9 11 4 1 1 5 9 3 9 19 peratures, concurrent12 but1 opposite Baltic2 3 Sea.1 6 2 Some4 of2 these6 7 17 records4 2 2 3 6 5 7 4 7 5 6 17 5 10 5 19 4 13 3 8 15 2 to those occurring in the8 3 North Sea, date7 back1 2 to3 5the2 121870s,2 6 2 i.e. 1to8 the 2 8 16 12 2 4 7 21 16 1 4 8 4 5 1 4 20 1 6 11 3 2 2 34 34 14 2 14 3 1 1 3 2 1 4 21 52 26 11 33 14 6 2 7 14 11 4 2 15 8 14 8 3 have been observed in the North foundation2 2 4 2 15 of12 the6 2 ‘Deutsche13 2 1 3 See-10 1 19 11 3 23 68 36 16 12 17 53 19 13 9 6 34 26 1 1 10 1 8 57 2759 Pacific, where – as in the North Sea warte’12 16 (German2 1 1 3 Maritime2 12 1 Observa-1 5 1 6 19 24 27 22 24 45 66 68 78 95 28 21 8 1 3 1 11 6 69 497 208 14 2 2 7 4 5 5 2 45 1 3 2 1 4 2 17 31 3 9 14 13 30 28 95 50 66 44 98 2 38 14 2 5 7 3 (Weijermann, 2005) – they give rise tory), predecessor of the Maritime 102 6607 147 230 128 110 1347086 2 1 1 5 62 11 3 4 3 3 1 20 2 1 2 1 7 38 12 3 8 18 10 37 87 63 54 26 20 37 64 60 43 75 11 4 202 117 327 578 1705412 127 508 to major changes in the1 marine1 Meteorological1 1 5 1 1 2 Office2 1 and6 12 the2 10BSH.29 9 7 7 18 57 46 44 13 15 47 68 76 21 35 43 65 18 34 62 61 175 409 633 320 250 431 30501542 ecosystem (Hare and 1Mantua, 2000). These early3 measurements,5 5 4 3 1 2 6 8 carried25 13 2 6 26 52 39 7 5 25 25 41 25 19 68 90 56 45 97 27 66 8 125 302 161 149 6089 1 3 3 2 5 4 2 3 2 1 3 41 16 5 22 38 52 13 3 6 6 10 14 22 21 91 60 72 1 8 The simultaneous and quasi-global279 out aboard light vessels, are con- 103 131 154 357 521 41222529171278 144 25182366 6461 5 2 1 1 2 2 2 1 5 28 28 1 3 38 12 5 11 9 13 12 9 8 4 1 17 27 1 100 105 346 208 248 132 11812299 appearance of these phenomena18 3 19 2 is tinued today3 2 by6 11the13 ten3 25 automatic49 34 3 4 8 8 14 11 12 18 18 42 21 10 59 20 86 83 537 100 164 3188119 8 12 3 1 4 26 30 40 37 19 6 4 5 10 5 9 9 31 14 18 30 58 77 64 66 98 3 25 evidence of interactions between the measuring stations that make up 111 216 2 1 5 33 22 9 3 4 1 1 6 68 5 6 30 12 47 62 46 35 10 31 54 1 2 1 5 219 259 2552 2519 dominant dynamical modes of1 the4 the BSH’s Marine Environmental2 4 2 5 10 10 5 3 45 29 3 1 124 climate system: the El Niño Southern Monitoring Network2 3 5in3 the North2 5 12 8 71 1 1 2 1 2 4 8 12 13 7 10 51 61 1 Oscillation (ENSO), Pacific/North Sea and Baltic Sea (MARNET). 43 3 1 6 4 6 7 5 15 19 46 3 23 157 American circulation pattern (PNA), 1 4 11 5 14 8 19 55 3 2816 Pacific Decadal Oscillation (PDO) and Number of WMO Voluntary Observing2 5 13 9 Ships21 42 15 16 8 7 1 5 5 5 19 19 25 9 27 12 North Atlantic Oscillation52˚N (NAO) in the German Bight in 2002, shown per 185 52˚N 18 9 5 17 36 36 9 63 138 136 (Wang et al., 2009). square on a 20-km grid 1 3 9 9 35 26 53 37 88 1216 cells 8 6 10 47 35 23 66 2 1 500 cells 2 2 3 1 1 2 1 4 43 32 4 15 10 72 cells 44 24 51 15 30 26 36 29 4 20 52 28 cells 194 18 28 32 6 1 1 2 135 14 2 18 68 4 168 3006 1 12 2 2 1 3 36 47 13 1877 395 # GTS OBS 2002 / North Sea 20km Grid 3 5 6 2 1 2 2 8 41 32 9 21 18 44 34 21 32 9 1 1 142 28 2 8 6 8 16 19 28 36 69 39 46 62 60 33 24 2 PL - 03/11/24 09:29 131 2943 42 19 29 9 13 29 44 39 25 51 50 77 33 46 28 9 7 115 101 25 33 13 41 47 39 33 52 31 65 24 20 5 5 2 1 2841 104 19 8 56 38 24 2 3 23 18 16 14 83 17 12 3 4 3 4˚W 0˚ 4˚E 8˚E 12˚E 3 Ocean observations Sea surface Sea surface temperatures (SST) in the North Sea 1968/69–2010/11

s Time series of annual North Sea sea surface from the mean (sigma = 0.46 K). The linear temperatures (SST, December to November), trend (0.3 ± 0.1 K/decade) is a misleading together with linear trend and regime shifts representation of how SST has changed over (stepped line). Blue if < 9.86°C (mean of base time. In fact, SST history is characterised by period 1971–1993), otherwise red. The right- jumps between temperature regimes, within hand y-axis shows the standard deviation which no clear trends can be discerned.

depth variations in ocean tempera- International context form part of the common European ture. The data sets are used to calcu- Ocean temperature data obtained by geoportal INSPIRE (Infrastructure for late other variables, such as the heat MARNET and the monitoring cruises Spatial Information in Europe). content of the water column and the are transmitted in the framework of Furthermore, ocean temperature depth of the thermocline. various co-operation agreements, data distributed over the GTS finds All these in situ temperature networks, projects and programmes its way into climate data sets, such measurements are recorded and to the databases and data portals of as the International Comprehensive archived by the German Oceano- international organisations. These Ocean-Atmosphere Data Set graphic Data Centre (DOD) at the include, among others, the North (ICOADS). BSH. The majority of the data is West European Shelf Operational distributed over the Global Telecom- Oceanographic System (NOOS) and munication System (GTS) of the the corresponding Baltic Operational World Meteorological Organization Oceanographic System (BOOS), both (WMO). The ocean temperature data, of which, as regional components together with other international of the European Global Ocean Ob- Required resources ship and buoy data that are obtained serving System (EuroGOOS) and the The operation of MARNET is a fixed ready-processed from the Deutscher Global Ocean Observing System component of the BSH budget. Wetterdienst (DWD), are used by the (GOOS), respectively, are part of the Ongoing BSH funding also finances BSH to carry out a weekly operational wider network of GCOS. The BSH is the regular monitoring cruises and analysis of sea surface temperatures currently developing a central geo- operation of nautical and hydro- in the North Sea. Although the fleet data infrastructure (GDI-BSH) as the graphic services. of Voluntary Observing Ships (VOS) maritime component of the German of the WMO has halved in size to federal geodata infrastructure less than 4,000 vessels since the (GDI-DE), that in turn is intended to 1980s, the density and frequency of data collection in the North Sea have remained stable or even increased. http://www.bsh.de

45 3.2 Salinity

Salinity is a property of the ocean known as a ‘conservative’ one (that only changes through mixing) and is therefore of great importance in oceanography for the identification of water masses. At the sea surface, salinity is modified through evaporation, precipitation and fresh water from the land (river runoff, glacial melt). Thus, it can be expected that climatic changes in the hydrological cycle of the atmosphere will be manifested in changes of surface salinity.

Climate trends Long-term records of surface salinity exist for various areas and regions in International context the North Sea, but most of these All measurements within German suffer from a severe lack of homo- territorial waters must be provided geneity regarding, in particular, data to the German Oceanographic Data accuracy in the past and data gaps Centre (DOD) for archiving. All data during the two world wars. Addition- are available from there for national ally, most long-term salinity measure- or international analysis free of charge. ment stations in the North Sea are Additionally, the DOD provides influenced by continental runoff and Measurements in Germany salinity data to international projects, the associated extremely high salin- Continuous and up-to-date informa- such as MyOcean, the European ity variability is making it difficult to tion about salinity in the German EEZ Coastal sea Operational observing detect any correlations between (North and Baltic Seas) is gathered and forecasting system (ECOOP), the changes in the hydrological cycle and within the framework of the regular North West European Shelf Oper- changes in the climate (increased monitoring activities of the Federal ational Oceanographic System flow of fresh water due to glacial Maritime and Hydrographic Agency (NOOS) and the free-drifting float melt or higher precipitation). (BSH) and in co-operation with the programme Argo. A typical example of long-term Leibniz Institute for Baltic Sea salinity records is the time series of Research, Warnemünde (IOW) at the the ‘Helgoland Reede’ (Helgoland automated MARNET stations (see Roadstead) which has been sampled link to web page). Salinity measure- since 1873. Here, the high variability ments are also collected by the BSH Legal framework in salinity is strongly associated with during monitoring cruises. Further Under the Maritime Shipping (Fed- continental runoff (Elbe plume) and monitoring cruises are carried out eral Competences) Act (SeeAufgG), meteorological conditions in the by various authorities and research the marine environment in general German Bight. These measurements, institutes of the coastal Länder, as well as the occurrence of changes carried out in the past manually on mostly as part of project-related in the marine environment is to be weather ships in the German exclu- measurement campaigns. All these monitored by the German Federal sive economic zone (EEZ), are now data are archived at the DOD. In Government. This includes the par- performed by automated systems. recent years, additional automatic ticipation in inspections made by the Long-term records of salinity and measurement stations have been European Union or other international other parameters are essential to installed in connection with off-shore organisations of which Germany is a detect and evaluate changes in the wind farms. member state insofar as such inspec- marine ecosystem. The northern part of the North tions are necessary to implement Sea is dominated by Atlantic waters, legal instruments of the European while its southern parts are influ- Union or fulfil the international com- enced by the Baltic outflow and the mitments of the Federal Republic of runoff of major European rivers, Germany. such as Thames, Rhine and Elbe,

46 3 Ocean observations Sea surface Surface salinity at the position of the lightship ‘Deutsche Bucht’ (DB)

s Surface salinity at the position of the lightship ‘Deutsche Bucht’ (DB) 1949–2011 (manned until 1986, thereafter unmanned with measurement chain)

with the consequence of great variation is an essential prerequisite for Required resources bility at all time scales. Autonomous fulfilling the task of monitoring the The operation of measurement sta- profiling systems (floats) have been marine environment. tions requires large logistical and collecting salinity measurements in Recently, Germany and interna- personnel resources. All measure- the world’s oceans in real time since tional co-operation partners have ment and maintenance activities 2000 within the Argo programme. In started to analyse ocean salinity depend mainly on the meteorological this context, responsibility for the using satellite data from the ESA’s conditions at sea, for which reason it co-ordination of Germany’s contri- Soil Moisture and Ocean Salinity is not always possible to perform bution lies with the BSH. Up-to-date satellite (SMOS) and the more regular maintenance. The measuring and comprehensive salinity informa- recent joint NASA/Argentinian system is quite often subject to tech- Aquarius/SAC-D satellite. Both mis- nical difficulties or loss of equipment. Positions of manned and unmanned sions have delivered first data sets Additional resources are also measurement stations the technology of which, however, needed to validate and improve t needs continued improvement satellite-based measurements of

Manned lighships until 1988 before the data can be scientifically salinity and to ensure that these data Unmanned MARNET station since 1989 Nordseeboje II analysed and used in model studies. can be assimilated in numerical The first results look promising but circulation models. the development of high-quality

Nordseeboje III products will need more time and Amrumbank much more and sustained scientific research.

Ausseneider Ems Deutsche Bucht

Fino 1 Elbe 2 Elbe 1 Elbe 3 Norderney Elbe 4 http://www.bsh.de/Vorlagen/ressources/nav_de/navigation2.jsp Aussenjade Minsenersand Borkumriff Weser Bremen http://www.bsh.de/de/Meeresdaten/Beobachtungen/MARNET-Messnetz/MARNET.jsp

20m

47 3.3 Sea level

Changes in sea level provide an important indicator for changes in the climate of the earth. The reasons for changes in sea level are very complex and arise mainly from the interaction between thermal expansion due to warming, changes in the volume of the ocean due to the melting of polar ice sheets, changes to glaciers and changes in the ocean circulation. Regional changes in sea level can differ substantially from the global mean due to, among other things, vertical movements of the solid earth (glacial isostatic adjustment, GIA).

Climate trends Baltic Seas is to be monitored by the In view of the high internal variability German Federal Government and the of sea level due to natural fluctuations Länder. Germany’s exclusive economic in air pressure and wind forcing, long zone (EEZ) is under the jurisdiction of time series of sea-level measurements the Federal Government. The tasks are needed to detect statistically sig- defined include the implementation nificant anthropogenic changes. Sci- of legal instruments of the European entific analysis has shown that records Union (e.g. water framework directive) going back at least 50 years are neces- as well as the fulfilment of internation- sary to resolve the decadal variability al commitments made by the Federal properly (Haigh et al., 2009). Republic of Germany (UNFCCC, Kyoto Within the framework of the protocol, GEOSS, GMES, GCOS). AMSeL project of the German Coastal Engineering Research Council (KFKI), the time series of 13 tide gauges Measurements in Germany along the entire German North Sea Ensuring the safety of the German coast have been combined in a high- coasts requires a system of local quality synthetic time series which tide-gauge stations to be in place represents the entire German Bight to monitor regional and local and spans the period 1843–2008. Most changes in sea level. In addition to of the individual time series included the tide gauges, satellite altimeter are much shorter, however, and it is observations of sea level need to of the utmost importance to continue be provided on a continuous basis. those measurements on a long-term Systematic sea-level measure- basis and additionally increase the ments that date back to 1843 come length of the time series by digitising from the tide gauge station at historical records from the archives Cuxhaven. While the older time s in order to obtain a better regional series only contain coarsely Location of the tide gauges along the German differentiation of sea-level change. resolved data of tidal high and low coast and in the tidally influenced parts of the This applies in particular to the con- waters, modern tide gauge stations rivers tinuation of the measurements from with digital recording technology satellite altimetry. offer high-resolution data at minute intervals. Currently, tide gauge technology has changed continually, measurements are carried out by from staff gauges to floating gauges Legal framework the Water and Shipping Offices with graphical and digital recording, Under the Maritime Shipping (Fed- (WSA) and other regional author- acoustic gauges, pressure and radar eral Competences) Act (SeeAufgG, ities at 165 stations along the gauges, all of which are still in use. § 1, par. 9, in the version of 26 July German North Sea coast and in the During the last 20 years, satellite 2002 (Federal Law Gazette I 2876)), the tidally influenced parts of the rivers. altimetry has come to offer global marine environment of the North and Over the years, measurement coverage of sea-level measurements

48 3 Ocean observations Sea surface Synthetic time series of mean sea level (mm) in the German Bight from 1843–2008

s The combined time series is based on the records from 13 selected tide-gauge stations with high-quality, verified data (Wahl et al., 2011). The graph shows annual means (black) and the adjusted non-linear trend (blue). The increase in sea level is relative to the land surface and takes account of the effects of uplift or subsidence.

International context Required resources Sea-level measurements along the The monitoring of the marine envir- German coast are part of the inter- onment in the North and Baltic Seas national tide gauge network GLOSS is regulated by the Maritime Shipping from space. In the deeper parts of (Global Sea Level Observing System) (Federal Competences) Act. However, the oceans and areas outside the which is operated under the auspices a substantial part of the development continental shelves, the satellite data of the World Meteorological Organ- and service work is still financed allow the determination of sea level ization (WMO) and the Joint Technical through national and international and its variability to an accuracy of Commission for Oceanography and projects within the framework of uni- one centimetre. The algorithms for Marine Meteorology (JCOMM) of versity research. To secure the sustain- using the satellite data to calculate WMO and IOC (Intergovernmental ability of such services it is neces- sea levels in coastal areas continue Oceanographic Commission of sary to establish long-term funding. to be refined within the framework UNESCO). It is the aim of GLOSS to It is also essential for coastal of international research projects. provide high-quality sea-level data protection that the satellite altimetry An important aspect of regional for use in both climate research and missions of the European Space analysis of sea level in the North Sea coastal research. The core network Agency (ESA) and the European is the large-scale distribution of ver- comprises 289 stations worldwide. Organisation for the Exploitation of tical land movements, which are an Germany contributes station data Meteorological Satellites (EUMETSAT) after-effect of the last ice age. Large- from the tide gauge at Cuxhaven. are continued and receive the neces- scale land uplift and subsidence are sary investment in infrastructure. superimposed on local water level To sustain coastal applications of changes and show mostly linear satellite altimetry it is necessary to trends on centennial scales. The provide sufficient funding to develop Federal Institute of Hydrology (BfG) and refine the required algorithms. has therefore begun to monitor vertical land movement and has equipped selected tide gauges with GPS antennas allowing direct measurements of land uplift and http://www.gloss-sealevel.org/ subsidence.

49 3.4 Sea state

Sea state is the term used for the height of wind-generated waves on the sea surface. Changes in wind conditions and storm intensity have a direct impact on the sea state. It is thus not a primary indicator of climate change, but constitutes an important parameter affecting adaptation strategies in maritime transport and coastal defence and in the offshore industry.

Climate trends Wave-measuring buoy with flash light Records of sea state observations by and antenna, 90 cm diameter seafarers have existed since the middle of the 19th century; the beginning of systematic shipboard observations dates back about 60 years. Many of the statistical analyses so far are based on such visual observations. However, long-term data series with a length comparable to that of Measurements in Germany tion. In recent years, additional moni- atmospheric parameters do not yet Reliable wave measuring technol- toring stations have been established exist for wave measurements. Cur- ogy did not exist until the 1960s. in connection with offshore wind rent monitoring stations were estab- The longest German time series farms. Besides these sea surface lished primarily for the benefit of originates from Helgoland station. measurements, remote sensing data shipping, pilotage services and coastal Beginning in 1989, it meets the from satellite-based measurements defence, but the data are also avail- 20-year criterion of GCOS for a using radar altimeters have been able for the purposes of research climatological time series. Other available since the 1980s. These institutions and industry. monitoring stations started oper- global radar data are available from The statistical-climatological ation later: Elbe in 1991, NSB-2 in ESA (www.globwave.org). importance of these data series still 1993, Sylt in 2002, FINO-1 in 2003 lies mainly in the validation of numer- (and Darßer Schwelle and Arkona Location of permanent wave monitoring ical wave models and their results. Becken in the Baltic Sea in 1991 stations in the German Bight and western Models, unlike the few monitoring and 2002 respectively). Baltic Sea: the station ‘Sylt’ is operated by stations, allow the generation of Additional wave measurements Schleswig-Holstein’s government-owned long, continuous time series cover- are carried out by the Länder author- company for coastal defence, national parks ing large areas. ities and by research institutions at and ocean protection (LKN-SH), the station However, precise measuring numerous sites in the coastal area, ’Darßer Schwelle’ by the Helmholtz-Zentrum methods are required to record ex- mostly in connection with projects Geesthacht (HZG), all other by the BSH. treme events and particularly high, and using different instrumenta- t dangerous single waves. Some years of the time series shown on page 51 cannot be analysed statistically because of too many data gaps. Over the two decades, there is no clear trend, neither in the mean wave heights nor in the th 95 percentile (P95). Slightly higher annual maxima in the last years are probably due to shorter measuring intervals, which allow the exact time of the highest sea state during a storm to be recorded more precisely.

50 3 Ocean observations Sea surface Significant wave heights at Helgoland 1991–2010

s Light grey: annual means;

dark grey: percentile P95 (significant wave height not exceeded during 95% of the year); International context red: maximum annual significant wave height The data from the permanent moni- Due to data gaps, the figures do not necessarily toring stations, together with other reflect the annual maximum that has actually oceanographic data, are exchanged occurred. within the framework of the European All monitoring stations (see map) Global Ocean Observing System use wave-following buoys that are (EuroGOOS) with the regional sections Legal framework elastically moored. The measure- of NOOS for the North Sea and BOOS In support of sustainable development data are transmitted to shore for the Baltic Sea, both part of the ment of shipping and maritime uses by radio, in some cases via satellite, GCOS ocean observing system. How- and the protection of the marine en- and processed automatically. They ever, none of the stations belong to vironment, the Federal Maritime and are made available on the Internet in the specifically designed GCOS Sur- Hydrographic Agency (BSH) collects near-real time at www.bsh.de/en/ face Network (GSN). Data transmis- and analyses maritime data and Marine_data/Observations/Sea_state/. sion is automatic on an hourly basis. makes them available to the public. The measurements record the The data are also transmitted hourly The general legal basis for these waves’ energy spectrum from which to the Deutscher Wetterdienst (DWD), tasks is the Maritime Shipping (Fed- important wave parameters, e.g. which distributes them through the eral Competences) Act (SeeAufgG). significant wave heights, mean wave Global Telecommunication System period and wave direction, can be (GTS) of the World Meteorological calculated by means of standardised Organization (WMO). The Marine procedures. Some stations also Environmental Monitoring Network Required resources record highest single waves. The in the North Sea and Baltic Sea There are good prospects that oper- significant wave height is the mean (MARNET), an automated monitoring ation of the existing monitoring height computed from the highest network operated jointly with the stations can be continued in future. third of all single waves measured. Leibniz Institute for Baltic Sea Research Measurements at sea are very ex- All these time series are thus (IOW) and the DWD to record oceano- pensive and technically demanding, homogeneous with respect to pos- graphic and other physical and chem- and the risk of equipment failure or ition, measuring method and data ical parameters, is an important tool loss is high. Maintenance of the sys- analysis, with the exception of the for measuring sea state. Responsi- tems cannot always be carried out on measuring interval. Measurements bility for the national centre for mari- schedule. This is reflected in numer- were initially made every three hours, time geospatial data, i.e. the German ous gaps in the data series. To keep but improved data transmission has Oceanographic Data Centre (DOD), data loss at a minimum, improved reduced the interval to 30 minutes lies with the BSH, which also co-ord- logistics and more personnel will be currently. This allows extreme situ- inates international data exchange. required. ations to be recorded more easily.

http://www.gloss-sealevel.org/

51 3.5 Sea ice

In polar regions, the ice on the sea has a strong influence on albedo and thus also on the energy budget. Sea ice acts as an insulating layer that reduces heat and nutrient exchange between the ocean and the atmosphere. Ice changes relatively slowly and, since the sea ice cover is relatively well known, it provides a good indicator of variability occurring at seasonal to longer time scales.

Climate trends Although relatively short, satellite- based time series of ice cover that first became available at the end of the 1970s are widely known to the public as they show a dramatic retreat of Arctic sea ice, which is very probably connected with anthropogenic climate warming. Direct observation of ice conditions along the German coast dates back to the end of the 19th century. Estimates of the Measurements in Germany annual maximum extent of ice cover Continuous ice observations have in the whole of the Baltic Sea date been carried out along the German back to the year 1720 and continue coast since the end of the 19th cen- to be updated. For the German Baltic tury. Since the winter of 1927/28, Sea coast the severity of ice winters ice maps of the German coast and can be reconstructed as far back as the whole of the Baltic Sea have 1300 with the help of historical docu- been compiled at least once a week. Legal framework ments. Long time series like these According to the Maritime Shipping already provide evidence of longer- (Federal Competences) Act (SeeAufG), term climate fluctuations, such as the German Federation is responsible the mediaeval warm period and the for the provision of ice information little ice age. services in German seawaters. The German Ice Service provides advice to shipping all over the world and is based in the Federal Maritime and Hydrographic Agency (BSH). Its history goes back to the end of the 19th century and the ‘Deutsche Seewarte’ (German Maritime Observatory). According to the Antarctic-Environ- mental Protocol Implementation Act (AntarktUmwSchProtAG), the BSH is also responsible for issuing Antarctic shipping permits. s Overview map of ice in the Baltic Sea dated 4 April 1929, i.e. the 87th ice map published in the second season

52 3 Ocean observations Sea surface Total volume of sea ice in relation to the area on the German Baltic Sea coast from 1879 to 2011

s International context Distribution of total volume of sea ice in The close co-operation among Baltic relation to the area on the German Baltic Sea Sea ice services dates back to 1925. coast from 1879 to 2011 For decades, even during the cold Source: Schmelzer & Holfort, 2011 war, daily data and reports were exchanged. Today, regular meetings are held and the ice services have a common website. On a global scale, there is a good level of collaboration among members of the International Ice Charting Working Group (IICWG), The most important ice parameters which organises international meet- measured are coverage and thick- ings where not only operational but ness; others include shipping condi- also scientific issues are discussed. Required resources tions and the form of the ice. The The ice services rely to a great extent Due to statutory obligations, funding data and the maps are archived at on satellite data and work closely for the fundamental work of the Ice the BSH, some of which already in with remote sensing agencies, such Service is relatively secure for the digital form. Information about cur- as the European Space Agency (ESA) future. Some of the satellite maps rent ice conditions is available free and the National Oceanic and Atmos- used by the BSH’s Ice Service are on the BSH website. pheric Administration (NOAA). The compiled by staff and student assist- For the last few years, global ice international regulation and standard- ants at universities, who provide this coverage has been continuously isation of operational ice information service on a voluntary basis. Other determined by the universities of services is undertaken by the Expert services and scientific studies rely Bremen and Hamburg from satellite Team on Sea Ice of the Joint WMO- on additional funding, mostly from data, with the results being dissemi- IOC Technical Commission for Ocean- the public sector, i.e. the Länder, the nated free of charge on the Internet. ography and Marine Meteorology Federation and the EU. In most cases, Scientific studies of sea ice are (JCOMM). The Global Digital Sea Ice however, the continuity of this fund- undertaken by the Alfred Wegener Data Bank (GDSIDB) maintains two ing is not secured. The continuation Institute, Helmholtz Centre for Polar international archiving centres for of satellite missions is of key import- and Marine Research (AWI) in Bremer- ice maps and other information, ance, especially but not exclusively haven and a few universities. Many located at the Arctic and Antarctic those carrying Synthetic Aperture of these are process studies, with a Research Institute (AARI) and the Radar (SAR) instruments, as well as global coverage, but not carried out National Snow and Ice Data Center the continued free availability of on a continuous basis. Long-term (NSIDC). satellite data for use by the ice measurements are performed mainly services and scientists working in in the Fram Strait and to the north of the field. this region.

http://www.bsh.de

53 3.6 Deep water formation

Surface water sinks into the abyss in a few key regions in the Atlantic, as part of the oceanic meridional overturning circulation. The volume of water transferred into the deep, i.e. the water mass formation rate, determines the capability of the ocean to absorb and store heat, fresh water and climate-relevant gases such as CO2. As it is not possible to measure the formation rates directly, temporal changes in the oceanic inventory of trace gases, such as chlorofluorocarbons (CFCs) and sulphur hexafluoride (SF6), are used to infer these formation rates.

Climate trends Analysis of trace gas measurements at s The oceanic key regions react very the Institute of Environmental Physics (IUP), sensitively to changes in the atmos- University of Bremen pheric forcing. Global warming is thus expected to significantly affect the formation of deep water and the meridional overturning circulation. This would have a great impact on German measurements formation in the Atlantic, i.e. the key the storage and transport of heat, Trace gas data (CFC-11, CFC-12 and regions of oceanic circulation. n fresh water and anthropogenic CO2 SF6) are used to calculate deep In the subpolar North Atlantic, in the ocean – with considerable water formation rates. The reason changes in the deep water forma- consequences for the sea level and is threefold: these gases have a tion rates have been subject to climate in Western Europe. This high long life in the atmosphere, show study since 1997. About every two sensitivity is also the reason for the increasing atmospheric concentra- years, the distribution of trace ocean’s high natural variability in tions and behave in the ocean like gases is measured for changes to response to natural fluctuations in noble gases. They are transferred calculate changes in the formation the atmosphere – which hampers the into the surface water through rate. At every survey, about 2,000 detection of fluctuations of anthro- air-sea gas exchange, sink with the to 3,000 tracer samples are ana- pogenic origin. Long data series are surface water masses into the lysed, partly directly on board the therefore needed to distinguish abyss in a few regions and are ship, partly in the home laboratory. between natural variability and long- distributed in the ocean’s interior The availability of suitable research term trends. by large-scale circulation. Since vessels, such as the FS Meteor these gases are chemically and and FS Merian, is essential. biologically inert, their concentra- n In 1986, trace gas measurements tions depend only on the year the were carried out for the first time water mass left the surface and on along the prime meridian in the how they are mixed in the depths. Southern Ocean; they have been Legal framework The tracking of anomalies in the repeated since then every 2 to 3 There is no legal framework. The concentrations is used to infer how years thanks to the research ice- measurement of trace gases in the quickly climate signals are spread- breaker FS Polarstern. This trace- ocean is part of the basic research of ing in the ocean. Climate models gas time series is also one of the universities and research institutes. predict a weakening of formation longest in the world. Further meas- The activity is funded by national and rates and related circulation, which urements have also been made in European third parties. would have a significant impact on the whole Atlantic in order to study the climate in Western Europe. the pathways of newly formed German measurements focus deep water and estimate the speed on the key regions of deep water of its spreading.

54 3 Ocean observations Open ocean Strength of the circulation (NAO index) and rate of deep water formation

s Top: Atmospheric fluctuations over the North Atlantic expressed as the air pressure difference in winter between the Icelandic low and the Azores high (North Atlantic Oscillation (NAO) index) n A further application of large- Bottom: Time series of the formation rate of scale trace gas measurements Labrador Sea Water (LSW), a main component is the calculation of storage of of the North Atlantic Deep Water (red), and the

anthropogenic CO2 in the ocean. International context transport index for the eastward transport in Like the other trace gases already The national measurement of trace the upper 2,000 m between Bermuda and the

mentioned (CFCs or SF6), it enters gases is part of international research Labrador Sea (blue). The inset globe shows the the ocean via air-sea gas exchange, activities, such as the WCRP’s CLIVAR LSW formation area and the main spreading bound up, however, in chemical programme, which focuses on climate pathways. Transports and formation rates and biological processes that are variability and predictability and the are given in Sverdrups (Sv; 1 Sv = 106 m3/s) difficult to assess. Therefore, an coupling between ocean and atmos- (update from Rhein et al., 2011). internationally proven method to phere. Additionally, the measure- calculate the amount of anthropo- ment is part of European research

genic CO2 relies on the distribution projects such as CARBOOCEAN and of trace gases. In the Atlantic, CARBOCHANGE. Germany is leading in the analysis Required resources and interpretation of trace gas The measuring of oceanic trace gases data, as well as in the number of including some of the technical per- measurements. sonnel required and technological The German oceanic trace-gas data development are funded through are part of European and internatio- temporary research projects; its con- nal data archives, and of the national tinuity is therefore not secured. Also, archive PANGAEA®. the measurements cannot be carried out without ship time on suitable research vessels (FS Meteor, FS Merian, FS Polarstern).

http://www.ocean.uni-bremen.de

55 3.7 Ocean colour

‘Ocean colour’ is a collective term for various physical and biological parameters derived from multispectral optical remote sensing data. Some of the most important parameters for monitoring the ocean are concentrations of chlorophyll, yellow substance (also known as gelbstoff or coloured dissolved organic matter) and suspended matter as well as turbidity and transparency or Secchi depth. The regular availability of information about the variability of these parameters over space and time is also of great importance for the detection and assessment of climate- related changes in the marine environment.

Climate trends Satellite-borne optical remote sensing began in the late 1970s. A greater variety of optical sensor has become available over the last 10 to 15 years. Therefore, time series long enough for climatological analysis Availability of the various satellite-borne are not yet available. However, for optical sensors several marine areas consistent time Source: Brockmann Consult series covering the last decade can (see list of abbreviations) be constructed. t

Measurements in Germany Optical satellite-borne measurements of ocean colour have been used for more than ten years for ocean monitoring in German waters, especially in the North and Baltic Seas and the adjacent North Atlantic. Concentra- tions of chlorophyll, yellow substance and suspended matter as well as turbidity and transparency or Secchi depth can be derived from multispectral optical data. Due to the different characteristics of marine water masses, algorithms must be applied that take account of local Legal framework the European Union or other inter- optical properties. Validation with in Under the Maritime Shipping (Fed- national organisations of which situ data allows provision of esti- eral Competences) Act (SeeAufgG), Germany is a member state insofar mates of the difference between the the marine environment in general as such inspections are necessary to two measurement methods. as well as the occurrence of changes implement legal instruments of the Because the availability of remote in the marine environment is to be European Union or fulfil the inter- sensing data is limited by cloud monitored by the German Federal national commitments of the Federal cover, moving multi-day, weekly and Government. This includes the par- Republic of Germany. monthly averages are used for moni- ticipation in inspections made by toring purposes. These data cover

56 3 Ocean observations Ocean composition Seasonal chlorophyll-a distribution in 2010 at Helgoland station

International context Many ocean colour products have been developed in the framework of international projects (e.g. ESA, EUMETSAT) and are provided directly or via a local service provider (German Aerospace Center (DLR)), research institutes, universities). The European Global Monitoring for Environment and Security (GMES) initiative has contributed substantially to the development of satellite-borne products. As well as the the whole seasonal cycle with the development of methods and user- Required resources exception of the winter months specific products, an infrastructure Today, a great part of the developing (due to the low angle of the sun) and, for the validation of data and GMES work and services is still financed by thanks to the spatial information downstream services (validation national and international research included, support the interpretation bureaus) has been established. In projects. To ensure the sustainability of data from fixed monitoring sta- parallel with the operational use of of the services, the users must share tions, such as buoys and platforms. the data, the algorithms are being a part of the costs in the medium The data support the validation and improved and refined and derived term. It is of extreme importance for development of numerical ocean products are being further developed measurement of ocean colour that models, especially suspended in research projects. the Sentinal-3 mission is launched matter and ecosystem models, and as soon as possible which will bring constitute, together with the model the replacement of the MERIS sensor and in situ data, an important on ENVISAT. The space component observation component. is secured until 2020; however, the funding of the ground component and downstream services is still under discussion.

http://www.bsh.de

57 3.8 Nutrients in the ocean

The nutrient substances nitrate, nitrite, ammonium, phosphate and silicate are of vital importance for the natural balance of the oceans, and without them biological growth would be impossible. Inputs from agriculture, industry and traffic, however, lead to increased primary production (eutrophication), which causes oxygen deficiencies and changes in the species composition. Meanwhile, there is good evidence that the effects of eutrophication are influenced by climatic changes.

Climate trends and Hydrographic Agency (BSH), Phosphate levels in riverine dis- which operates an automated moni- charges and in German Bight sea toring network and routinely carries water have clearly decreased since out monitoring cruises. the mid-1980s. Owing to this devel- Fulfilment of national obligations opment, current coastal concentra- is governed by the German Marine tions are only about 60% above Monitoring Programme for the North the assessment level of 0.6 µmol/L Sea area (BLMP), international obli- (Brockmann et al., 2007). gations by agreements made under Riverine discharges and winter the Oslo-Paris Convention for the concentrations of dissolved inorganic Protection of the Marine Environment nitrogen (DIN) have also decreased of the North-East Atlantic (OSPAR) since the mid-1980s. However, current and, since recently, the Marine Strat- levels still clearly exceed the assess- egy Framework Directive (MSFD). ment level of 12 µmol/L (Brockmann et al., 2007) by a factor of 3. The yearly variations in silicate Nutrient measurements in the German concentrations are a reflection of the Bight: the distribution of the nutrients is natural variability. representative of the entire water column, Long-term trends indicate that which is well mixed in winter due to storm the measures taken to reduce nutri- events. ent loads have been effective even t though assessment levels have not yet been reached.

Legal framework Under the Maritime Shipping (Fed- eral Competences) Act (SeeAufgG, § 1, par. 9 and 11, § 5, par. 1, No. 4 and 5) in the version of 26 July 2002 (Federal Law Gazette I 2876), the marine environment of the North and Baltic Seas is to be monitored by the German Federal Government and the Länder. Germany’s exclusive economic zone lies under the jurisdiction of the Federal Government. DIN ( mol/l) Near surface Chemical and physical monitoring is January 2011 carried out by the Federal Maritime

58 3 Ocean observations Ocean composition DIN nutrient concentrations in winter in the coastal waters of the German Bight

s Time series of winter nutrient concentrations in the coastal waters of the German Bight at a salinity of 30 and confidence interval (interval forecast) of 95%

International context Another legal basis for the pro- Marine environmental protection is tection of the marine environment in an issue of global concern. With the Europe is the EU Water Framework adoption of the corresponding im- Directive (WFD), which, however, plementation act, the OSLO-PARIS lacks detailed regulations concerning Convention (OSPAR) came into effect the marine environment due to the for the North Sea in 1998, obliging fact that the directive was developed the contracting states to regular especially for inland, transitional and reports to the Commission. To meet coastal waters as well as groundwater. this requirement, Germany makes Consequently, a special marine the data contained in the Marine strategy has been developed for all Environmental Database (MUDAB) European waters in the form of Direc- available at EU level. tive 2008/56/EC of the European Parlia- ment and of the Council establishing a framework for community action in the field of marine environmental Measurements in Germany Nutrient concentrations are policy (Marine Strategy Framework The BSH has routinely carried out influenced primarily by hydro- Directive) adopted on 17 June 2008. nutrient measurements in the German dynamic processes resulting from Bight for more than 30 years in order the mixing of river water and sea to monitor the nutrient situation and, water, causing salinity distribution in particular, changes of nutrient to be influenced by the interaction inputs and their direct and indirect of different parameters, such as Required resources impacts on the marine environment. riverine discharges, the direction of Monitoring of the marine environ- The data collected allow assessment net transports (residual currents) ment is assured under the Maritime of the effects of nutrient inputs and increasing dilution. This is Shipping (Federal Competences) Act (e.g. from agriculture, industry and apparent from the inverse linear (SeeAufgG). Fulfilment of national transport) and possible climate correlations between salinity and obligations is additionally governed changes. nutrient levels and which are suit- by the German Marine Monitoring The spatial distribution of dis- able for interannual comparisons Programme (BLMP) whereas inter- solved inorganic nitrogen (DIN = and trend estimates (Körner and national agreements are ruled by the nitrate + nitrite + ammonium) shows Weichert, 1991). Oslo-Paris Convention. As an inter- a pattern which is typical for all nationally co-ordinated monitoring soluble nutrient parameters. High programme, the BLMP will in future nutrient levels are found close to the be integrated into the MSFD. coast, mainly as a result of significant nutrient inputs from the Weser and Elbe rivers. In the central German Bight, levels are clearly lower due to http://www.bsh.de dilution with North Sea water.

59 3.9 Oxygen conditions in the North Sea

All higher life in the ocean depends on oxygen dissolved in water. The amount of oxygen dissolved in water is much smaller than that in air. One litre of water contains only about 1/20 th of the amount of oxygen in the same volume of air. Surface water is usually well supplied with oxygen. If there are prolonged periods of good weather during the period of algal growth in spring, oxygen supersaturation is even possible. During the second half of the year, the decomposition of organic material, a process that consumes oxygen, may lead to a deficiency of oxygen in the bottom layer.

Legal framework Measurements in Germany The data provide information about Under the Maritime Shipping (Fed- Since 1964, oxygen levels have current oxygen levels in the water eral Competences) Act (SeeAufgG, been routinely measured by the column. They are included in the § 1, par. 9 and 11, § 5, par. 1, No. 4 BSH during its North Sea monitor- international eutrophication assess- and 5) in the version of 26 July 2002 ing journeys. Additionally, oxygen ment of OSPAR (OSPAR Comprehen- (Federal Law Gazette I 2876), the sensor measurements with a high sive Procedure, 2005-3) and in the marine environment of the North temporal resolution have been initial assessment of the German and Baltic Seas is to be monitored conducted since 1989 at the BSH’s North Sea (implementation of the by the German Federal Government unmanned lightship stations UFS Marine Strategy Framework Direct- and the Länder. Germany’s exclusive TW Ems and UFS German Bight. ive (MSFD), Directive 2008/56/EC of economic zone lies under the jurisdiction of the Federal Government. Chemical and physical monitoring is carried out by the Federal Maritime and Hydrographic Agency (BSH), supervised by the Federal Ministry of Transport, Building and Urban Development (BMVBS), by autonomous monitoring stations and regular monitoring journeys.

Oxygen (% saturation) bottom September 2003

60 3 Ocean observations Ocean composition Oxygen saturation measurements at the unmanned lightship TW Ems

s 2010 oxygen saturation/oversaturation (in %) at 6 m and 30 m at the unmanned lightship UFS TW Ems in the North Sea

International context All measurement data collected within the framework of the German the European Parliament and of the Climate trends Marine Monitoring Programme Council of 17 June 2008). The first oxygen measurements in (BLMP) are stored in the MUDAB Dissolved oxygen concentrations the North Sea were made as far back Marine Environmental Database and in bottom water decrease through- as the beginning of the last century reported to the International Council out the summer due to microbial (Gehrke, 1916). Records from that for the Exploration of the Sea (ICES). decomposition of dead organic time show the occurrence of oxygen The data are thus available for inter- material (remineralisation), which undersaturation at about 50–60% national eutrophication assessments may lead to oxygen deficiency. A due to typical summer stratification and climate debates. stable thermocline preventing oxygen in the water column. In future, the data will be compiled transport from upper water layers Sensor data of high temporal in international Reporting Sheets as may cause severe oxygen depletion resolution from UFS German Bight part of the MSFD. in the near-bottom layers. Oxygen and UFS TW Ems monitoring sta- saturation below 80% may have a tions, which have been recorded negative impact on the growth of since 1989, continuously reflect the bottom fauna. Oxygen concentrations prevailing oxygen conditions. These Required resources below 20% saturation cause mortality data are essential for international Monitoring of the oxygen situation (Bauerfeind et al., 1986; Rosenberg assessments of eutrophication and in the marine environment is assured et al., 1991). in the global climate change debate. under the Maritime Shipping (Fed- eral Competences) Act. National obligations are specified in the German In summer 2003, a prolonged heatwave and Marine Monitoring Programme calm weather led to near-bottom oxygen (BLMP) and will be integrated into levels of 38% (3.2 mg/l) in the outer German an internationally co-ordinated moni- Bight. Conditions for benthic organisms living toring programme under the MSFD. in sediment and on the seabed, e.g. crabs, clams, snails, sea urchins and worms, became increasingly difficult.

http://www.bsh.de

61 4.1 Runoff

The most comprehensive data possible on water resources, in addition to their importance today for climate studies and climate-impact research, have long been essential in the context of a wide range of socioeconomic and ecological concerns. The validity of statements about these issues depends on the quality of the data material from which they are derived: outputs cannot be better than the data on which they are based.

Climate trends as to those of the Länder. The Federal Ancient civilisations constructed Water Act (WHG) is the basic legisla- water gauges and documented the tion, which comprises the opening observations made from them. This clauses of many of the regulations was often a prerequisite for the exist- drawn up by the Länder. Federal ence of societies that depended on the navigable waterways, together with organised and efficient use of water, their water level and high water infor- the basis of life. There is a 52-year mation services, are regulated by the time series of water levels of the Federal Waterways Act (WaStrG). Nile from as long ago as 2800 B.C. The use of data is regulated by the In Germany, water gauges have Federal Environmental Information been used since the 18th century. Act (UIG). The oldest and longest time series of water levels are from the Elbe at Magdeburg (since 1727) and the Rhine at Düsseldorf (since 1766). Long runoff time series are also Measurements in Germany The German Hydrological Year- essential for today’s technological The hydrological measuring net- book (DGJ) publishes daily data society. They enable spatial and work in Germany comprises the from 1,172 water gauges on runoff temporal variation of runoff to be overarching federal water gauge alone, corresponding quarterly and analysed, usable water resources network, operated by the German long-term totals, and information and high and low water risks to be Federal Waterways and Shipping from a large number other measuring calculated, and the impacts of human Administration (WSV), as well as stations, including data series for activities (climate change, changes the measuring stations operated water levels, tides, water temperature in land use) to be investigated. They by 15 of the German Länder or and suspended matter. provide the basis for the develop- local authorities and third parties The average length of runoff time ment and deployment of water (e.g. water utility companies). It series in the DGJ is 55 years. How- management strategies, concepts consists of about 4,250 hydrological ever, as standard practice, the time and decisions. gauges, of which about 3,000 also series are cut off at 1931, even when provide throughflow measure- older data exist: in almost all basins, ments. This network monitors and for example, there are observational keeps records on the entire inland records from water gauges going waterways system (down to the back more than 100 years; the largest Legal framework level of ditches), in total around number are in the Rhine (20 stations), As a federal country and member of 500,000 km of waterways. Danube (17) and Elbe (15) basins. the European Union (EU), the Federal The WSV supervises the large In addition to the DGJ, other Republic of Germany is subject to shipping waterways in the basins of important archives and distribution water-related regulations under EU the rivers Rhine, Danube, Elbe, Oder, centres of data from water gauges law (Water Framework Directive, High Weser and Ems, where it operates on federal waterways include the Water Framework Directive) and has about 620 water gauges, of which 163 databases of the regional WSV to respond to federal concerns as well also measure runoff or throughflow. offices and the overarching data

62 4 Terrestrial observations Hydrosphere Mean runoff at Cologne water gauge (Rhine) since 1821

s Daily, yearly and decadal runoff averages (Q in m3/s) since 1821 (part of a time series International context going back to 1816) recorded by the water The Global Runoff Data Centre gauge on the River Rhine at Cologne (GRDC, see Chapter 5.2), based in (MQ = average runoff) Germany, receives runoff data from more than 800 stations operated by federal authorities and the Länder, which sustain the GRDC database and contribute to the water data archives of research groups in the EURO-FRIEND water programme of UNESCO. The GRDC is the conduit for contributions to the Global Ter- restrial Network for River Discharge Required resources (GTN-R) maintained by GCOS, the The demand for hydrological sta- Global Terrestrial Observing System tistics is growing, due to the ever- (GTOS) and the World Meteorological increasing importance of hydro- Organization’s (WMO) programme logical parameters for politics and for Hydrology and Water Resources. society. To this end, there is an Selected real-time data on water urgent need to develop modern levels and runoff are used for medium- methods for statistical analysis of and long-term flood warnings by the hydrological data, as well as for European Flood Awareness System improved resource provisioning. archives held by the Federal Insti- (EFAS), based at the EU’s Joint tute of Hydrology (BfG). The Länder Research Centre in Ispra, Italy. maintain their own databases for stations that they operate. http://www.bafg.de

63 4.2 Water use

In Germany, demographic and technological developments as well as changes in the climate will heavily influence the demand for water and its availability, so that knowledge about trends in water consumption by the main user groups, i.e. industries, private households and agriculture, is gaining in importance.

Trends surface-water resources. The aim of Long time series of data illustrate sustainable water management in the temporal variations in water accordance with the WHG is the pre- uses and provide a basis for further servation of the ecological functions analyses and studies. of water for the benefit of the general Over the past 20 years, the vol- public and in the interest of indi- umes of water withdrawn by thermal viduals. Any use of water, including power stations, mining and process- abstraction for different purposes, ing industries as well as public water requires an official permit. The WHG supplies have decreased by roughly defines the nationwide applicable 30%. This is because of technological requirements that are enforced by advances as well as systems of mul- the authorities of the Länder. tiple water utilisation and recycling. Public water supplies provide about 99% of private households and small businesses with drinking Measurements in Germany conducted every three years. The cur- water, which is mainly withdrawn Data on water abstraction by rent legal basis is the Environmental from groundwater. The daily drink- municipal enterprises for supplies Statistics Act of 16 August 2005. The ing-water consumption in private to private households and small data are evaluated for different ad- households was around 122 litres businesses as well as by all types ministrative and non-administrative per inhabitant and day in the year of processing and manufacturing area units and are used for public 2007 and thus has been reduced by industries, power utilities and information and as an aid to political 25 litres per person since 1990. This agricultural businesses are collected decision-makers in matters of water development can be explained mainly at Länder level by the corresponding conservation. The main users of these by changed consumer behaviour. statistical offices. Processing and data are national and international Average consumption figures in the evaluation of the data at the federal authorities, institutions and associ- German Länder reveal a wide range, level is done by the Federal Stat- ations, as well as interested private from 135 litres per inhabitant and istical Office (DeStatis). Surveys are persons. day in North Rhine-Westphalia to 85 litres in Saxony. Water resources and water use in Germany in 2007

Potential water resources 188 billion m3 = 100%

Legal framework Water use in Germany is ruled at an overall federal level by the Federal Water Act (WHG) of July 2009 (latest amendment in December 2011), which implements the European Water Framework Directive (WFD) and – along with subsidiary national direct-

ives – regulates the protection and Source: Federal Environment Agency (UBA), 2009 management of groundwater and Data: DeStatis, 2009; Federal Institute of Hydrology (BfG), 2006

64 4 Terrestrial observations Hydrosphere Water abstraction for public water supply, industries and thermal power plants

32.0

Source: DeStatis, 2009

International context Scientific assessments of water scarcity and water shortage investigate the ratio between water resources and water demand. International The water user groups industry institutions, such as the Organization (including power utilities), private for Economic Cooperation and households and agricultural busi- Development (OECD), the European nesses withdraw different volumes Commission (EC) and the European of water from aquifers and surface Environmental Agency (EEA), evalu- water bodies. Industrial and agri- ate the national data from certain cultural businesses often operate angles in order to highlight problems their own water-tapping facilities to in the water sector and to derive meet their demands, while private recommendations for action. At the households are usually supplied by same time, they pool the data pro- municipal waterworks. vided by the individual states in inter- The greatest group of water users national databases and make this are thermal power plants, which information tool available to all abstract water for cooling purposes interested users worldwide. and return nearly the whole amount The German data on water quan- after use back into the natural water tities are transmitted to these organ- cycle. The second rank among water isations every other year as part of Required resources users is held by mining and process- the joint questionnaire project of the In publications on non-public water ing industries. EU’s statistical office Eurostat and supply, data about water abstraction Thus, the total volume of water the OECD (Questionnaire on the state for agricultural irrigation should abstraction of 32.1 billion m³ corres- of the environment in the EU’s Mem- appear as an economic sector of its ponds to less than 20% of the poten- ber States). These results are also own. tial water resources. This means that made available to the EEA and the It would be desirable to adapt the presently more than 80% of the water United Nations Environment Pro- frequency of national data polls to resources remain unused. gramme (UNEP). European standards.

Source: Federal Environment Agency (UBA), 2009 http://www.bafg.de http://www.uba.de Data: DeStatis, 2009; Federal Institute of Hydrology (BfG), 2006

65 4.3 Groundwater

Groundwater meets about 75% of Germany’s demand for drinking water. The groundwater resources that are annually recharged by precipitation are unevenly distributed among the regions of the country. Therefore, large conurbations in Germany are often connected to remote public water supplies. In order to safeguard the use of available water resources, the German Länder are responsible for the monitoring and evaluation of groundwater, including both quantity and quality. Maintaining the good chemical status of groundwater requires not only the protection of groundwater quality but also the prevention of damage to groundwater-dependent surface water bodies and terrestrial ecosystems. The river basin management plans drawn up by the Länder describe the current condition of the aquifers and define goals and actions in the context of EU regulations.

Trends More significant changes were Measurements in Germany It is relatively difficult to determine observed at 130 observation wells The Groundwater Services of the long-term trends in Germany from unimpacted by human activity in Länder operate full-coverage ground- long time series of groundwater Saxony between 1976 and 2006. The water observation networks. The levels, because most measuring sta- graph shows a clear, mainly negative data are pooled, managed and made tions are impacted by human activ- trend through the whole year as well available by databases maintained ity. In one of its studies, for example, as through the seasons. by the responsible agency in each the North Rhine-Westphalia State In Mecklenburg-Western Pomer- Land (e.g. the Agency for the Environ- Agency for Nature, Environment and ania, the overall trend in ground- ment and Geology in Hesse). These Consumer Protection (LANUV) could water levels was also more or less Land-specific databases are mostly use only 416 measuring wells out negative from 1980 to 2006, although web-based geo information appli- of 4,000 for such purpose. In the it should be noted that in this case cations and in some cases can be period 1970 to 2008, trends at these not all observation wells were accessed by the public on the sites were very uneven, with nearly unaffected by human activity. Internet. equal numbers of positive and nega- Key activities of these networks tive trends and no distinct regional include monitoring groundwater pattern. In summary, results showed levels, groundwater quality and more negative trends, i.e. decreasing untreated water in drinking-water groundwater levels, in the months protection areas. The networks col- from April to July and an opposite lect data on water use for enforce- tendency in August and September. ment of the Water Usage Payment However, the variations detected Act (also known as ‘water penny’), amounted to only a few millimetres and on aquifers in accordance to the per year and are therefore of purely Water Framework Directive (WFD) of statistical interest. the European Commission.

66 4 Terrestrial observations Hydrosphere Analysis of trends in Saxony from 1976 to 2006

2.75

International context The Federal Institute for Geosciences and Natural Resources (BGR) is a partner in the World-wide Hydrogeo- Legal framework logical Mapping and Assessment Pro- The Water Framework Directive gramme (WHYMAP), an initiative of (WFD) and its daughter, the Ground- UNESCO and the World Meteoro- water Directive (2006/118/EC, GWD), logical Organization (WMO) carried Observed data for water-manage- constitute the principal legal founda- out in co-operation with the Inter- ment are a key prerequisite for plan- tion for groundwater protection in national Groundwater Resources ning by water utility companies and Germany. At a national level, ground- Assess-ment Centre (IGRAC). The for the definition and enforcement of water protection is regulated by the aim of the programme is to produce a standards by the authorities. Federal Water Act (WHG) and the Fed- global map of groundwater resources. To monitor the chemical condition eral Soil Protection Act (BBodSchG). On the basis of this map, a geo infor- of groundwater, the Länder operate Since the reform of the German Con- mation system (GIS) will be developed 5,682 observation wells as back- stitution in 2006, the Federation has to make all groundwater-relevant data ground stations in undisturbed aqui- had competing legislative powers on available in digital form. At the Euro- fers and another 3,979 operational issues relating to the water budget, pean level, the information network stations in aquifers affected by the which means that legislation enacted EUROWATERNET, established by the environment. A further 8,960 wells by the Länder may be overridden by European Environment Agency (EEA) are used to monitor quantitative federal acts. The legal basis for quanti- in collaboration with the European indicators of groundwater condition. tative and qualitative monitoring states, has been in operation since A monitoring network consisting of and evaluation of the groundwater 1998. about 800 stations provides data for situation in the Länder is given by reports to the European Environ- the corresponding water legislation ment Agency (EEA). adopted by each Land in response to the WHG and the amended Ground- Required resources water Ordinance of 2010. Modern methods for processing spatial data using GIS are required and will become increasingly important, alongside Internet-based user- friendly interfaces for evaluation and presentation of the data.

http://www.bafg.de

67 4.4 Stable isotopes in precipitation

Ratios of the most frequently occurring stable isotopes of water in precipitation (i.e. 18O/16O (d18O) and 2H/1H ((d2H)) vary over space and time, depending on the source of the water and the conditions (moisture and temperature) during cloud formation and rainfall. Absolute ratios and seasonal variations in the distribution of water isotopes measured in precipitation at individual locations reflect local temperature, continentality, latitude and altitude. Stable isotopes thus provide information about the sources of water, the history of the rainfall event and air mass trajectories as well as temperature changes and climate change effects.

Climate trends Deutscher Wetterdienst (DWD). The Long-term data on stable isotopes at data obtained are the property of the high spatial and temporal resolutions IGOE and are available to the DWD are of great importance when study- upon request. Publication of IGOE ing seasonal differences in precipi- data needs approval by the contact tation and changes in air mass tra- person; data are freely available to jectories. Stable isotopes of water the public after publication. in precipitation are also used as environmental tracers in hydrological modelling. To obtain accurate results, Measurements in Germany Greifswald in 2002), Seehausen, this requires input time series that Samples taken monthly or when Artern, Dresden, Görlitz, Kahler Asten, correspond to at least four to five precipitation events occur have Passau) and event-based samples at times the mean residence time of been collected for isotope analysis three stations (Arkona, Norderney, water in the system. The empirical, at 29 meteorological stations all Hohenpeissenberg), all operated by linear relationship between tempera- over Germany from 1973 to the the DWD. Event-based samples are ture and stable isotopes in precipi- present (see map). Since 1978, also taken at the institute’s own tation, which can be safely identified 16 of these stations (Cuxhaven, station in Neuherberg. only from long-term data sets, allows Braunschweig, Berlin, Bad Salzuflen, To obtain a monthly, mixed us to identify regions impacted by Emmerich, Koblenz, Wasserkuppe, sample, a station’s daily precipitation climate change. Hof, Trier, Würzburg, Karlsruhe, samples are accumulated and mixed Stuttgart, Regensburg, Konstanz, over the month in a 5,000 ml PE Weil am Rhein, Garmisch-Parten- bottle. Every month, a volume of kirchen) have been operated within 1,000 ml is taken of this cumulative Legal framework the Global Network for Isotopes in sample and stored separately in Since 1997, stable water isotopes in Precipitation (GNIP), a joint pro- 1,000 ml PE bottles to be sent to the precipitation have been measured at gramme of the International Atomic IGOE for analysis once a year. the Institute of Groundwater Ecology Energy Agency (IAEA) and the During sampling and shipping, care (IGOE) at the Helmholtz Zentrum World Meteorological Organization is taken that the lids are closed München - German Research Center (WMO). Since 1997, monthly properly to avoid evaporation. All for Environmental Health (HMGU) samples have been collected at precipitation samples are analysed according to a contractual agree- nine stations (Schleswig, Fehmarn, at the IGOE for d18O (± 0.15 ‰) and ment between the HMGU and the Neubrandenburg (replaced by d2H (± 1 ‰) contents in triplicate.

68 4 Terrestrial observations Hydrosphere Monthly d2H concentrations in precipitation over Berlin (measured and calculated values)

s Monthly measured d2H concentrations in precipitation over Berlin (diamond dots and dashed line) with calculated 12-month running mean (solid line)

International context The findings of the German isotope network are included in the IAEA’s and WMO’s joint Global Network for Isotopes in Precipitation (GNIP). After publication, the data are available online through the Water Isotope Sys- tem for Data Analysis, Visualization and Electronic Retrieval (WISER), which contains time series of stable isotopes in precipitation around the globe. Without a doubt, the German Required resources data set of water isotopes in precipi- Analysis of the stable isotopes in tation is unique in the world on ac- water at the IGOE will be continued. count of its quality and continuity, with The IGOE offers the infrastructure high temporal (monthly to daily data, (analytical instruments) and man- partly covering more than 35 years) power (technical assistant) to analyse and spatial resolution (29 stations d18O and d2H precipitation samples of Monthly samples since 1973 (GNIP) equally distributed across the country). the DWD free of charge. The data Monthly samples since 1997 (DWD) Daily samples since 1997 (DWD) have been used for ongoing research Daily samples since 1997 (HMGU) at the IGOE (Maloszewski et al., 2006; Stumpp et al., 2007; Stumpp et al., s 2009; Stumpp and Maloszewski, 2010) Sampling network for the analysis of water and in collaborative studies with other isotopes in precipitation research partners (e.g. University of (yellow: stations that have been monitored Freiburg, Technical University Dresden, on a monthly basis since 1973 and are part of Karlsruhe Institute of Technology). the GNIP database; green and red: stations operated by the DWD on a monthly and event basis, respectively; purple: event-based station Neuherberg, operated by the IGOE since 1997 http://www-naweb.iaea.org/napc/ih/IHS_resources_isohis.html with daily sampling)

69 4.5 Snow cover

Snow cover is a major factor influencing the climate. Therefore, the parameters snow depth and new snow depth as well as the related parameters type of snow cover, state of soil and water equivalent are of particular interest in the context of the expected anthropogenic climate warming, especially in the fields of tourism, water management and transport.

Climate trends Against the backdrop of global climate warming, most stations have recorded a decrease in the snow cover season, but with large variations from year to year depending on the total amount of precipitation, which by its nature is also highly variable. The few outliers in the one or other direction (such as in 2010 or Measurements in Germany 1989) have no effect on the general The Deutscher Wetterdienst (DWD) trend towards less snow cover, operates a network of surface especially in the last 20 years. weather stations classified into climate and precipitation stations, of which about 2,000 currently take snow measurements. The number of DWD stations, from which snow measurements are available, varies over the time and depending on the monitoring programme. On average, the availability of digital data of snow parameters from climate stations starts in 1951. The precipitation stations in the former Federal territory Legal framework have registered and archived data The Law on the Deutscher Wetter- on soil state, weather events and dienst (§ 4) gives the DWD responsi- snow depth since about 1979. The bility for short- and long-term regis- s data archive includes snow data from tration, monitoring and evaluation of Distribution of stations where snow depth stations in the territory of former meteorological processes as well as and other snow parameters are recorded East Germany in electronic format the structure and composition of the since about 1991. atmosphere, and for the operation of Other snow measurements are the required measurement and only available in paper form and are observing systems. currently being digitised and archived

70 4 Terrestrial observations Cryosphere Number of days with snow cover in Germany

s Area averages of the annual number of days with snow cover in Germany for the period 1951–2011

in the framework of various projects. International context From before 1950, the data archive The synoptic reports from 180 sta- therefore contains no more than a tions are distributed worldwide on a couple of time series and from routine basis. For a selected number before 1935 only very few single of stations, quality-checked monthly digitised time series of snow meas- climatological information is made urements. available in the form of CLIMAT Alongside the DWD stations, reports. The stations at Frankfurt, there exist additional snow measure- Hamburg, Hohenpeissenberg and Required resources ment programmes which are carried Lindenberg are part of the GCOS The sustained operation of existing out by other institutions or individual Surface Network (GSN). measurement stations can be persons. However, only minor parts regarded as substantially secured. of these data series are included in However, the level of automation the DWD’s database, as they often must be driven further, the high do not meet the high standards of number of staff further reduced and representativeness, measurement limited to observations at air fields methods and continuity of operation. and climate reference stations. The The snow depth is measured resulting change in the measurement manually using a snow measuring methods from spatially averaged board with snow stake or measuring measurements to sensor recording stick. With the change to automated at single ground points is expected weather stations, manual measure- to cause inconsistencies in the time ment was replaced by snow depth series of snow cover. sensors.

http://www.dwd.de

71 4.6 Glaciers and permafrost

The results of alpine glacier research show clear evidence of climate change. Whereas the glacier retreat during the first half of the 20th century can be related to non-anthropogenic influences, the rapid decline over the past 30 years proves the influence of mankind on glaciers and climate, with consequences also for permafrost in mountain regions.

Climate trends glaciers over the long term. The legal The mapping of the Bavarian gla- framework for the Commission’s ciers, the results of which suit the work comprises § 2 par. 1-3 and § 19 application of the geodetic method, par. 2 of the statute of the BAdW. began in 1889 for Blaueis, in 1892 for The observation of permafrost falls Northern and Southern Schnee- within the legal competence of the ferner and in 1897 for the Watzmann Bavarian Environment Agency (Law Glacier. The shortest time series is on the competence of state develop- that for Höllentalferner, starting in ment and ecological questions, § 5) 1949. Stretching from 2,368 m to for the treatment of questions in the 1,910 m in altitude (1999), Blaueis is field of geological engineering. the lowest and northernmost alpine glacier (Hagg, 2008). The geodetic method shows a loss of 80% in area Measurements in Germany for Southern Schneeferner and 73% The KEG monitors all five Bavarian for Northern Schneeferner between glaciers – Northern and Southern 1892 and 2009. Watzmann Glacier Schneeferner, Höllentalferner on lost 79% of its area between 1897 Zugspitze and Watzmann and Blau- and 2009; the area of Blaueis shrank eis in the Berchtesgaden region – from 16 ha in 1889 to 8 ha, and that using the geodetic method. This of Höllentalferner has lost 18% since method is based on the comparison 1950. The mean thicknesses lie of geodetic measurements made between 16.8 m (Northern Schnee- approximately every ten years, ferner) and 3.8 m (Blaueis). Northern which provide the changes in gla- Schneeferner had the greatest losses cier area and surface, thus enabling in volume between 2006 and 2009, the calculation of the mean alti- Watzmann Glacier the largest gains tudinal change over the given between 1970 and 1980 (Hagg et al., period. Assuming a mean ice dens- 2008). These changes in mass correl- ity, the mass balance is thereby ate well with the results for other derived (see graph). For the period glaciers of the eastern Alps (see 1962/63 to 1968/69, the direct gla- difference between mass gains Chapter 6.2). ciological method was also applied (mainly due to precipitation in winter) to one of the five glaciers, namely and losses (mainly due to melting in Northern Schneeferner. This method summer). For all Bavarian glaciers, supplies annual mass balance sums measurements of ice thickness are Legal framework for the glaciological year (from available that have been carried out The Glaciology department of the 1 October to 30 September of the between 2006 and 2010 using geo- Commission for Geodesy and Glaci- following year) derived from the radar technology. ology (KEG) of the Bavarian Academy of Sciences and Humanities (BAdW) is the sole national institution that http://www.lfu.bayern.de/geologie/massenbewegungen/projekte/ studies the behaviour of German

72 4 Terrestrial observations Cryosphere Time series of geodetically determined mass balances of the five Bavarian glaciers and Vernagtferner in Austria

NSF = Northern Schneeferner SSF = Southern Schneeferner Zugspitzplatt with Northern Schneeferner HTF = Höllentalferner (August 2011) WMG = Watzmann Glacier BEI = Blaueis (near Berchtesgaden) VF = Vernagtferner (Austria)

The thickness of the bars represents the International context average mass change per year (unit: cm water The results of glacier measurements equivalent per year) for the given period, made by the KEG are regularly pre- calculated from altitudinal variations (m/a) by sented in the two most important applying a mean ice density of 900 kg/m3. Permafrost, i.e. continuous publication series for glaciological One can clearly recognise the mass gains underground temperatures below data. These are issued by the World phase in the seventh and eighth decade of the 0°C, plays only a small role in Glacier Monitoring Service (WGMS) 20th century (blue), the periods of losses of Bavaria. Its thawing can result in in Zurich, Switzerland, and by the glacier mass (red) after 1889 and 1980 and the damaging rockfalls and settlements. Institute of Arctic and Alpine Research close-to-balance period for Blaueis between In a study within the Alpine Space (INSTAAR) and the National Snow 1889 and 1924. The bottom row shows the project PermaNET, Zurich University and Ice Data Center (NSIDC) in values for Vernagtferner in the Ötztal Valley, ran a model which showed that the Boulder, USA. The German results Austria (see Chapter 6.2). area mainly affected by permafrost are thus made available to the most is the northern rocky sides of the important international organisations: region, with a total area of approx. UNEP, WMO, UNESCO and ICSU. 65 km2. The dimensions have for the Very close co-operation exists with first time been presented on a map the universities of Innsbruck (Austria), that depicts the probability of perma- Zurich (Switzerland) and Milan (Italy). frost using different shades. The Research projects are undertaken Required resources Bavarian Environment Agency (LfU) together with national and inter- Currently, the glaciological work at has run an observatory station on national groups in Central Asia. The the BAdW is funded through the the Zugspitze summit since 2007, permafrost surveys are carried out Academies Programme of the Union which will supply long-term docu- by the LfU in co-operation with uni- of the German Academies of Sciences mentation of changes in permafrost. versities, agencies and governmental and Humanities. This funding ends departments in Austria, Switzerland, with 2015 and the BAdW is striving Italy and France within the frame- to transfer funding responsibility to work of the Bavarian PermaNET the Bavarian state; this is not as yet component. secured.

http://www.permanet-alpinespace.eu http://www.bayerische-gletscher.de

73 4.7 Albedo

Surface albedo represents an important component of the radiation balance at the earth’s surface. Trends in surface albedo influence radiation from the earth’s surface and thus also the climate system. Effective cloud albedo defines the albedo of clouds relative to cloudless sky. Even a small percentage change in effective cloud albedo would have an effect comparable in magnitude to the anthropogenic greenhouse effect; a long-term change would therefore have huge consequences for the interpretation of temperature measurements.

Climate trends The CM SAF (see Chapter 5.9) currently has a 23-year time series for surface albedo and effective cloud albedo, which will be extended to 30 years within the framework of the EUropean Reanalysis and Obser- vations For Monitoring (EURO4M) Legal framework project (www.euro4m.eu). Long series Measurements in Germany The work of the Satellite Applica- enable trends and extremes of sur- and in Europe tion Facility on Climate Modelling face albedo to be analysed, which, Comprehensive data on surface (CM SAF) is embedded, on the one in Germany, are generally related albedo of a sufficiently high quality hand, in the legal framework of the to variations in winter snow cover. are only obtainable from satellite or Deutscher Wetterdienst (DWD); on This may be the reason why, on the reanalysis data. Currently available the other, it is undertaken in accord- basis of the 23-year time series, no reanalysis data have a very coarse ance with contractual agreements clear trend in surface albedo can be spatial resolution (> 50 km2). Com- between the European Organisation discerned. prehensive high-resolution data are for the Exploitation of Meteorologi- By contrast, trends in effective at present only available from satel- cal Satellites (EUMETSAT) and the cloud albedo can be clearly identified. lite observations. In Europe, provi- DWD. CM SAF is tasked with long- The inset map shows that the magni- sion of high-quality data on surface and short-term registration, monitor- tude of the trends in solar irradiance albedo at high temporal and spatial ing and evaluation of meteorological can be in the order of several W/m2 resolutions is assured by Satellite processes as well as the structure per decade. Until now, however, this Application Facilities (SAFs), financed and composition of the atmosphere, parameter has been hardly taken by the national meteorological ser- and with the provision, archiving into account by climate monitoring and documentation of correspond- programmes. The main reason for ing meteorological data and other this has been the lack of data. Effect- products in accordance with § 4 of ive cloud albedo cannot be deter- the Law on the DWD. Detailed work mined from surface measurements.

plans and task specifications are 7 set out in accordance with these 6 aims in a five year contract between 5 EUMETSAT and the DWD, with the 4 3 participation of the concerned part- 2 ner organisations of CM SAF. 1 Trends in solar irradiance (1982–2005) 0 -1 resulting from long-term changes in -2 effective cloud albedo -3

74 4 Terrestrial observations Biosphere Temporal variability of surface albedo

s Hovmüller diagram of temporal variability of surface albedo in the pre-alpine region (areal average over latitude 9.9° to 12.9°E) for the month of March from 1987 to 2009. The marked temporal and spatial variation in snow cover in the pre-alpine region is clearly revealed by periods of high surface albedo (yellow/red colours). vices and EUMETSAT, such as those International context on Land Surface Analysis (LSA SAF) The products and procedures of the and Ocean and Sea Ice (OSI SAF). CM SAF not only serve the aims of Long time series of surface GCOS, but are also relevant for other albedo, the basis for analysis of cli- international programmes such as matologically relevant trends and the World Climate Programme (WCP) extremes, are currently only avail- and the World Climate Research Pro- able from CM SAF and EUMETSAT gramme (WCRP). They are essential (Govaerts, 2008). for the activities undertaken by the The creation of comparable qual- Group of Earth Observations (GEO) ity raster data from surface measure- and Global Monitoring for Environ- ments is not possible due to the low ment and Security (GMES). CM SAF Required resources spatial density of measuring stations. is also involved in European initia- A general problem consists in the In Germany, there is only one ad- tives, such as the European Space lack of scientific capacity for analysis equately equipped measuring station Agency’s (ESA) Climate Change Initia- of the data sets. This is essentially with long-term data on surface albedo tive and several other EU projects due to lack of core funding for uni- (Falkenberg), which is operated by (such as EURO4M). versity appointments, which makes the DWD. sustainable research almost impos- Comprehensive data on effective sible. Creating a long time series of cloud albedo of a sufficiently high albedo measurements from satellite quality are only obtainable from sat- data would require about 48 person- ellite or reanalysis data. With respect months as well as several terabytes to reanalysis data, the above com- of digital storage capacity. A one-off ments on surface albedo apply here analysis of the data set would require as well. a further 48 person-months.

http://www.cmsaf.eu http://landsaf.meteo.pt/ http://www.osi-saf.org/

75 4.8 Soil carbon

Vast amounts of carbon are tied up in the soil. Large and/ or long-term changes in soil carbon reservoirs and their release as carbon dioxide (CO2) or methane (CH4) into the atmosphere could have serious consequences for the climate. The largest soil carbon reservoirs are found in wetlands and peatlands. These are mostly located in permafrost regions or in the tropics. The total mass of soil carbon is however still very uncertain and recent estimates of the carbon content of different soil layers are urgently required.

Legal framework Under the terms of the United Nations Framework Convention on Climate Change (UNFCCC), Germany has committed itself to report on anthropogenic sources and sinks of greenhouse gases, and on reservoirs of carbon in soil and biomass (UNFCCC Trends Art. 3.3, 4.1, 4.2 and Decision 3/CP.5), On the basis of data from the national including soils used for agricultural forest soil survey (BZE Wald), carbon purposes. The international regulatory reservoirs in Germany can be extrapo- framework (IPCC 1996, 2000, 2003) lated and annual rates of change requires countries to provide data on Measurements in Germany calculated. Data on changes in carbon major carbon sources. In Germany, BZE Wald is a component of the reservoirs in forest soils were pre- these include soils used for agriculture National Soil Survey (BZE), which sented in the National Inventory and forestry, as well as built-up areas undertakes surveys of representa- Reports (NIRs), but not taken into con- and certain land use changes. How- tive areas and intensive long-term sideration for the accounts. Further ever, there is no consistent legal basis monitoring of case study areas research into the effects of forest for collection of soil carbon data. (Level II plots). BZE Wald records conversion and forest management BZE Wald is legally prescribed by data at about 2,000 sampling points on the carbon budgets of forest soils the German Federal Forest Act (§ 41a) throughout the entire country on a is not possible. Given that no further and also provides inputs for reports systematic 8 × 8 km grid. Measure- inventory will be conducted until submitted within the framework of ments were taken at the sampling 2025, changes between 2006 and the International Co-operative Pro- points for the first inventory (BZE 2025 are difficult to predict. gramme on Assessment and Moni- Wald I) carried out between 1987 The German agricultural soil toring of Air Pollution Effects on and 1993, and for the second inven- survey (BZE-LW) is an ongoing pro- Forests (ICP Forests) of the United tory (BZE Wald II) between 2006 ject and includes a one-off sample Nations Economic Commission for and 2008. The Länder collected and survey. At present, there are no plans Europe (UNECE). The agency respon- analysed data on soils, crown con- for follow-up inventories. The first sible for BZE Wald is the Federal dition, vegetation, foliage and forest regional interim results of this project Ministry for Food and Agriculture nutrition; the results were passed will be available from the end of and Consumer Protection (BMELV). to the Thünen Institute of Forest 2012. The Ministry has charged the Thünen Ecosystems for evaluation at a Institute of Forest Ecosystems with national level. nationwide co-ordination and evaluation of the survey. There are no regulations govern- ing the BZE-LW, which is conducted by the Thünen Institute of Climate- Smart Agriculture under the auspices of the BMELV.

76 4 Terrestrial observations Biosphere Carbon reservoirs in above- and belowground biomass

s Carbon reservoirs in above- and belowground biomass in 2008 (left); total changes in carbon reservoirs (middle) and changes per hectare (right) between 2002 and 2008 Source: Inventory Study 2008 and Greenhouse Gas Inventory for forests

The agricultural soil survey International context BZE-LW is the first nationwide, con- At a European level, a 16 × 16 km sistent and representative survey of grid is used to examine a subsample carbon reservoirs in the upper 100 cm of the BZE Wald data in a compara- of agricultural soils. It records the tive analysis within the framework of soil carbon reservoirs at about 3,200 the ICP Forests programme. Standard sampling points in arable lands, data collection methods for inter- Required resources pastures, gardens and specialised national comparison are set out in There is still insufficient research crop areas throughout the whole of the ICP Forests Manual. German into the impacts of climate change, Germany. Sampling points were se- laboratories have successfully taken and mitigation measures, on forest lected using a nationwide, randomly part in international ring tests, which soils. In particular, intensive effort generated, systematic 8 × 8 km grid. ensure that the data is comparable. should be made to research the soil Germany plans to contribute to Parties to the UNFCCC are under- water balance. Existing forest moni- the European research infrastructure taking partially comparable inventory toring programmes can provide the ‘Integrated Carbon Observation and monitoring programmes; how- data required. Within the framework System’ (ICOS) through a project of ever, there is no internationally stand- of BZE Wald, medium-term evalu- its own, ICOS-D. ardised methodology. This limits the ation of the second forest soil con- extent to which data sets from differ- dition survey is assured. A follow-up ent countries can be compared and survey is currently planned for 2025. evaluated. At a European level, the The German agricultural soil Land Use/Cover Area Frame Survey survey (BZE-LW) is an ongoing pro- (LUCAS) will also provide uniform ject and includes a one-off sample baseline data on carbon reservoirs in survey. At present there are no plans soils. for follow up inventories.

http://icos-infrastruktur.de/ http://www.lucas-europa.info/

77 4.9 Forest fires

In Germany, the pine forests of the eastern regions, which have a more continental climate, are most at risk of forest fires. A relatively dry state of vegetation, which may occur after a sufficiently long rainless period, is one of the preconditions of a forest fire. It is expected that with climate change summers will become dryer, causing the combustibility of forest floors to increase.

Trends With some limitations, it is possible into forests when the danger of fire to extract information on combust- is high. Special regulations control ibility of vegetation, climate impact, the burning of plant waste and pre- speed of response and efficiency of ventive burning of fields. In accord- prevention measures (i.e. the success ance with various administrative or failure of early warnings, fire de- agreements, the Deutscher Wetter- tection and fire fighting) from the dienst (DWD) provides forecasts of long-term records of the number of fire-weather danger. forest fires and extent of burned areas. For a more comprehensive climatological interpretation long-term data sets of forest-fire indices, which rate weather-dependent combustibility of forest floors, are also needed. The indices are calculated using fire- danger rating models populated with Measurements in Germany meteorological data relevant for forest Information on forest fires, i.e. place fires (e.g. air temperature and humid- of ignition, extent, cause, time when ity, precipitation and wind). The the alarm was raised and firefighting frequent occurrence of a very large begun, canopy type and extent of number of fires with large extents of damage are registered by fire bri- burned area can be a sign of deficits gades and forest authorities of the in the technical equipment of fire Länder and are condensed to monthly fighters and a proof of the necessity summaries. Excerpts are forwarded to restructure forest-fire suppression to the Federal Office for Agriculture activities, initiate forest conversion and Food (BLE), which issues the measures and improve early-warning annual statistics for Germany. These models. statistics provide a valuable summary of the fire situation in all German Länder and serve to support the stra- tegic focus on fire prevention and fire suppression. After the once-in-a-hundred-years fires in Lower Saxony in August 1975, Legal framework annual fire information became more According to article 70 of the German important. As a consequence, the Basic Law, responsibility for fire pro- current advisory and statistical Forest fires in 2010 tection and emergency management frameworks have been developed. 100 lies with the Länder. Their laws on fire During recent years, the establish- Number Area (in ha) protection regulate how to control ment of the camera-based FireWatch 0 fire hazards while forest laws enable system has significantly improved Source: BLE the banning of open fires and entry automatic forest-fire detection and

78 4 Terrestrial observations Biosphere Annual number and area of forest fires in Germany during the period 1977–2010 according to the forest-fire statistics for the whole of Germany

1,000

Source: BLE Forest fire near Ossendorf on 20.07.2006

reporting. To provide a modern International context infrastructure for fire detection and Once a year, in accordance with the suppression and see to continuous specifications of the European Forest maintenance and improvement of Fire Information System (EFFIS), all the detection and reporting systems forest-fire data from moderately to is a permanent key task in the pro- highly fire-prone regions of Germany vision of services for the protection are reported to the European Com- of life and property. mission’s (EC) Joint Research Centre (JRC) in Ispra, Italy, where the data of Required resources the Member States are reprocessed, The registration of statistical informa- quality checked and merged into tion on forest fires is done at local European forest-fire statistics. Based and regional level by forest author- on these data sets, a European re- ities and fire departments as part of gional risk classification is made in their routine work. The costs are order to manage financial support for borne by the Federation and the forest protection. In addition, EFFIS Länder, which are also responsible data are used for model validation. for the compilation, presentation Independently of EFFIS, the web- and distribution of data. The funds site of the Global Fire Monitoring needed are considered as secured. Center (GFMC) in Freiburg, Germany, The costs for meteorological fore- provides information on the forest- casting of forest-fire danger are fire situation in Germany. borne by the DWD. s Digital camera of the FireWatch system for forest-fire detection Source: Ministry for Food, Agriculture and http://www.dwd.de http://www.fire.uni-freiburg.de/ http://effis.jrc.ec.europa.eu Consumer Protection of Lower Saxony

79 4.10 Soil moisture

Soil moisture is a central parameter for weather forecasting, climate research, agricultural and forest meteorology, hydrology and flood forecasting. Area-covering information on soil moisture is an important initial condition for the development of operational weather forecasting models, especially of precipitation. Knowledge of current and future soil water availability in agricultural and forest areas as a function of the influence of soil type and climate is an essential basis for planning current and future management measures. Knowledge of the spatial distribution of soil moisture is indispensable for flood forecasting by the competent authorities.

Climate trends Continuous measurement of soil moisture using techniques that automatically record measurements has only been possible since about Measurements in Germany Despite the development of time 1991–1992. A summary of the current Measurement and model calcu- domain reflectometry (TDR) and state of measurement technology lations of soil moisture and its tem- other automatic recording tech- can be found in Stacheder et al., poral dynamics are undertaken not niques, continuous measurement of 2009, for example. Continuous series only by the DWD but also at per- soil moisture at different soil profile of soil moisture measurements are manent agricultural and forest soil depths is expensive and requires great important for the further develop- observation plots (BDF II) by effort. Since 1998, measurements of ment and testing of soil moisture regional agencies. In addition, uni- this kind have been conducted by budget models, such as Hydrus-1D versity and non-university research the DWD’s Lindenberg Meteorological (Simunek et al, 2008), and for testing institutions, such as the Leibniz Observatory – Richard Assmann the soil module of the DWD’s small- Centre for Agricultural Landscape Observatory (MOL-RAO) at the scale weather forecasting model for Research (ZALF), conduct measure- Falkenberg intensive measurement Germany, COSMO-DE. ments and model calculations on site (Beyrich et al., 2006). The DWD experimental plots (e.g. Wege- calculates daily integrated values for henkel, 2005) soil moisture at 0–60 cm depth for different crops and soils on a year- round basis at about 500 weather stations, using the agrometeorological model for the calculation of Legal framework current evapotranspiration (AMBAV) The activities of the Deutscher developed by the DWD’s Braun- Wetterdienst (DWD) are governed by schweig Agrometeorological the Law on the DWD. Long-term Research Centre (ZAMF). Direct, monitoring of soil moisture in agri- nationwide measurement of soil cultural and forest areas is carried out in accordance with the provisions of German soil protection law and EU regulations. http://www.gosic.org http://www.zalf.de

80 4 Terrestrial observations Biosphere Daily precipitation and soil moisture totals measured at the experimental plot in Müncheberg

s Daily precipitation (Prc) in mm/d; soil moisture, simulated and calculated using time domain reflectometry (TDR) and gravimetry (gravim.), in cm3/cm3 at depths of 0–30 cm (swc 30), 30–60 cm (swc 60) and 60–90 cm (swc 90) from 01.01.1993–31.12.1998 at Müncheberg experimental plot (altitude 62 m a.s.l.; geographical coordinates: 52°51.5’N, 14°07’E) moisture at a higher spatial International context (30 × 30 m) and temporal resolution, Internationally, area-covering soil by radar satellites such as the moisture analyses are assured, inter environmental satellite ENVISAT, is alia, by the Satellite Application still impossible or subject to severe Facility on Land Surface Analysis limitations (e.g. Koyama et al., 2010). (LSA SAF); data can be accessed For the moment, directly measured via the Global Observing Systems soil moisture data at coarser spatial Information Center (GOSIC, www. resolutions (10 x 10 km) are available gosic.org/). from satellite platforms, such as the Measurement series from experi- ESA’s Soil Moisture and Ocean Salinity mental and permanent soil observa- (SMOS) satellite. More information tion plots in Germany are not always can be found at www.bit.ly/1bgSh8R. gathered by data centres. A global In the field of numerical weather data centre and international soil forecasting, areal data on regional moisture measurement series are Required resources soil moisture are calculated from available at www.gosic.org/content/ Measurement and evaluation of soil models using measured land surface gcos-terrestrial-ecv-soil-moisture. moisture data requires considerable temperatures. For examples of the A further international data centre material and human resources. data generated see www.eumetsat. that holds data on soil moisture is int/website/home/Data/Products/ located at the European Organisa- Land/index.html. tion for the Exploitation of Meteoro- logical Satellites (EUMETSAT, www.eumetsat.int/website/home/ Data/Products/Land/index.html).

http://www.umweltbundesamt.de/themen/boden-landwirtschaft/boden-schuetzen/boden-beobachten-bewerten

81 4.11 Phenology

Phenology has to do with the periodically recurring patterns of growth and development of plants over the course of a year. The onset dates of characteristic phases of plant development (phenological phases) are observed and recorded. These are closely related to weather and climate and are therefore important indicators of the impact of climate change on the biosphere.

Climate trends Among the stations in the phenological data bank held by the Deut- scher Wetterdienst (DWD), 474 have records of observations covering more than 50 years, in 164 cases even more than 60 years (between 1951 and 2010). However, the existence of records over a number of years does not mean that all phenological phases were continuously observed during the period. It was possible to reconstruct data sets before 1951 from historical obser- Germany, but also in other European vations. Some phenological records countries. This gave rise to a Europe- held by the research station at Geisen- wide monitoring network, as well as heim on the river Rhine go back to a number of regional networks in before 1896. These show a marked Germany. shift towards earlier flowering times The first long-term nationwide over the past 60 years. phenological observation network in Germany was set up by the Biological At least 1 year of observations Institute for Agriculture and Forestry 50 or more years of observations of the Reich in 1922. The network was run by this institute until 1936, Legal framework when it was taken over by the In addition to ruling the responsibility Measurements in Germany Meteorological Service of the Reich for the operation of measurement The Societas Meteorologica and further developed by Dr. Fritz and observing systems for recording Palatina carried out systematic Schnelle. meteorological processes, the Law on phenological observations as early In 1946, phenological observations the DWD (§ 4(1), No. 5) also enjoins as between 1781 and 1792. How- were resumed by the meteorological the registration of meteorological ever, the real breakthrough in services in the US and Soviet zones. interactions between the atmosphere phenology occurred in 1882, when Subsequently, these monitoring net- and other areas of the environment the German university professor works were run by the Meteorological as another duty of the DWD. Herrmann Hoffmann and his Service of the former German Demo- colleagues drew up and published cratic Republic (MD) and the DWD guidelines for the observation of founded in 1950 and 1952, respective- phenological phases, thereby ly. The two monitoring networks and laying the foundations for standard- their data archives were brought ised observations, not only in together in 1990.

82 4 Terrestrial observations Biosphere Onset of flowering of hazel in Geisenheim since 1950

Co-operation in Europe Germany is a member of the Euro- pean Phenological Network (EPN) and also contributes, through observations in 32 gardens, to the monitoring programme of International Phenological Gardens (IPG). In 1996, responsibility for German participation in this monitoring network was transferred from DWD to the Hum- boldt University in Berlin. In 2003, the DWD was heavily involved in the initiation of the European Cooperation Thus, the DWD has an extensive in Science and Technology project archive of phenological data at its COST725, whose main task was to disposal. Alongside annual obser- establish a European-wide reference vations, the database collects immedi- data base of phenological observa- ate data, i.e. records submitted as tions. The DWD also participates in soon as the phenological phase the follow-up project, the Pan Euro- Required resources under observation occurs. These pean Phenology database (PEP725), The phenological monitoring net- data, that provide up-to-date infor- which was set up by the Austrian work relies largely on volunteers. mation on plant development, are Central Institute for Meteorology and However, their number has declined used primarily for pollen count Geodynamics (ZAMG), the Austrian over past decades; there are cur- forecasts and advice to farmers. Federal Ministry of Science and rently about 1,250 honorary observers. The annual observations, which Research and the Economic Interest A few years ago, about 60 main are used for climate research, are Grouping of European National phenological observer positions contained in the DWD’s data bank Meteorological Services (EUMETNET). were established at DWD weather and cover the period 1951 to the The main aim of PEP725 is to promote stations to complement the work of present. Currently, about 1,300 pheno- and support phenological research the volunteers. In order to continue logical observers contribute to the by making available an annually to benefit from people’s willingness monitoring programme, which pro- updated pan-European data bank, to assume honorary posts of this vides information on about 160 pheno- providing unlimited open access to kind, appropriate publicity measures logical phases of wild plants, agri- phenological data for science, research are required. The IPG monitoring cultural crops, fruit trees and bushes, and training (www.pep725.eu). network is also run by volunteers. and grape vines.

http://www.dwd.de

83 5.1 The Global Precipitation Climatology Centre

With its archive of quality-controlled monthly in situ (rain gauge-based) precipitation observation series, the largest in the world, the Global Precipitation Climatology Centre (GPCC), operated by the Deutscher Wetterdienst (DWD), has built up a unique and worldwide renowned capacity in the field of global land surface precipitation analysis and monitoring. The GPCC offers a number of different analysis products tailored to various requirements of its users, such as, for example, the ‘Full Data Reanalysis’ products (some of which extend back as far as 1901). All GPCC products are freely available on the Internet and have gained reference status for a wide spectrum of hydro-climatological applications.

Global measurements

Significance for GCOS monitoring product which uses the Because of the high importance of rain gauge/in situ observations ex- a reliable precipitation diagnosis changed through the WMO’s Global for the quantitative assessment of Telecommunication System (GTS). the global water cycle, the World The GPCC fulfilled its terms of refer- Meteorological Organization (WMO), ence, stipulated in WMO’s Technical upon recommendation by its Com- Document WMO/TD No. 367, well missions for Climatology (CCl) and enough to become a permanent Hydrology (CHy), has initiated the component of GCOS. Within the joint setting up of the Global Precipitation GCOS/GTOS activities, the GPCC Climatology Project (GPCP) as a con- also is a partner centre for the Global tribution to the Global Energy and Terrestrial Network for Hydrology Water Cycle Experiment (GEWEX) (GTN-H); on grounds of its evalu- and the World Climate Research Pro- ations of the CLIMAT reports collected gramme (WCRP). Given the limited through the GTS, it furthermore acts quality of purely satellite-based as the German GCOS Surface Net- precipitation monitoring over land, work Monitoring Centre (GSNMC) in the GPCC was mandated to provide issues regarding the precipitation a monthly grid-based precipitation parameter.

Spatial distribution of the 67,283 stations available for the GPCC’s precipitation climatology (December 2011) in terms of density of stations on a 1° evaluation grid

http://gpcc.dwd.de

84 5 International data centres Data coverage of the different GPCC products across the last 110 years

s Shown in colours: regularly issued First Guess (FG) and Monitoring products and the continuously growing data coverage of the Full Data Reanalysis product from version 3 to 6 released in 2005, 2008, 2010 and 2011 (1987 is the foundation year of the GPCC)

International context logical Satellites (CGMS), which is an The GPCC conducts global climate association of all satellite operating monitoring for the atmospheric agencies and was founded 40 years Essential Climate Variable (ECV) ago with the goal of keeping meas- ‘precipitation’. As a member of the urements comparable across plat- Atmospheric Observation Panel for forms. The GPCC’s preliminary ‘first Climate (AOPC), the GPCC reports guess’ product is utilised by the FAO annually to this advisory body of for the purposes of drought warning. GCOS. In addition, the GPCC is a The global full data reanalysis data component of the Global Terrestrial set supports the agendas of the Observing System (GTOS), co-spon- International Hydrology Programme sored by WMO, the United Nations (IHP) of UNESCO and the Hydrology Educational Scientific and Cultural and Water Resources Programme Organization (UNESCO), the Inter- (HWRP) of WMO. The homogenised national Council for Science (ICSU), VASClimo V1.1 data set and its suc- the United Nations Environment cessor, the Homogenized Precipi- Programme (UNEP) and the United tation Analysis (HOMPRA) data set, Nations Food and Agriculture are suitable for climate research in Organization (FAO). With its monthly the field of global precipitation trend monitoring product, the GPCC is analysis for recent decades. established as a long-term partner in 0 1 2 3 4 6 8 10 15 20 30 50 100 the GEWEX project of the WCRP. Number of stations per grid Moreover, its reliable provision of Required resources station-based reference precipitation The GPCC has been operated by products has made it an essential the DWD without interruption since partner of the International Precipi- 1989, demonstrating the sustained tation Working Group (IPWG), a joint character of the engagement. No working group of WMO and the change in the status quo is currently Coordination Group for Meteoro- foreseeable.

85 5.2 The Global Runoff Data Centre

The Global Runoff Data Centre (GRDC) currently holds mean daily and monthly river discharge data for more than 8,000 stations globally. These data are collected and maintained in direct support of the climate-related programmes and projects of the United Nations system and the international research community working on climate change and cross-boundary water resources management.

Significance for GCOS River discharge plays an important role in driving the climate system, as the freshwater flow to the oceans may influence the thermohaline circulation. The statistics for river discharge are an indicator for Global measurements climatic change and variability, as they reflect changes in precipitation and evapotranspiration and are influenced in the longer term by changing land use. River discharge data are also required for the calibration and validation of global climate and impact models, trend analyses and socio-economic investigations. Monthly records of river discharges are generally sufficient to estimate continental runoff into the ocean, while statistical analysis of river discharge data and impact evaluation of extreme events require data at daily resolution. The GRDC has con- ceived a network of river discharge stations near the downstream ends of the largest rivers of the world. Today, this network, known as the Global Terrestrial Network for River Discharge (GTN-R), forms a baseline Global distribution and availability network for GCOS and the Global of the 8,131 GRDC discharge stations providing monthly data Terrestrial Observing System (GTOS). (as of 5 January 2012)

86 5 International data centres Availability of historical discharge data in the GRDC database

s Availability of historical discharge data in the GRDC database (number of stations per year providing monthly data (left) and daily data (right))

International context contributes its river discharge data The GRDC was formally established to a number of international research in 1988 at the Federal Institute of programmes, such as the Global Hydrology (BfG) and operates under Energy and Water Exchanges Project the auspices of the World Meteoro- (GEWEX) and the Climate and Cryo- logical Organization (WMO). It is a sphere (CliC) project of the WMO’s German contribution to the World World Climate Research Programme Climate Programme - Water (WCP- (WCRP). Through its contribution Water) of WMO and the United to the Global Terrestrial Network – Nations Educational Scientific and Hydrology (GTN-H), the GRDC is Cultural Organization (UNESCO). linked to the Global Earth Observa- The activities of the GRDC are moni- tion System of Systems (GEOSS). tored by an international steering committee with members from WMO, UNESCO, the United Nations Environment Programme (UNEP), Required resources the International Association of The BfG is responsible for running Hydrological Sciences (IAHS) and the GRDC. This ensures the funding partner data centres advising it on of the GRDC’s core functions. Add- the basic orientation of its work. itional resources are required to Resolutions 21 (WMO Congress XII, extend data acquisition activities, to 1995) and 25 (WMO Congress XIII, further develop the GTN-R baseline 1999) mandate the GRDC to collect network and to develop the full river discharge data at global level in potential of the GRDC and its rele- a free and unrestricted manner and vance to the scientific community close co-operation with the national working on climate variability and hydrological services. The GRDC global change.

http://grdc.bafg.de

87 5.3 The World Radiation Monitoring Center

The World Radiation Monitoring Center (WRMC) is the central archive of the Baseline Surface Radiation Network (BSRN). The objective of the BSRN is to provide data on short and long-wave surface radiation fluxes of the best possible quality currently available to support the research programmes of the World Climate Research Programme (WCRP) and other scientific projects.

Dome of a pyranometer

Significance for GCOS In 2004, the BSRN was designated as the ‘global baseline network for surface radiation’ for GCOS. The high-quality, uniform and consistent Global measurements measurements throughout the BSRN network are used to: n monitor the short-wave and long-wave radiative components and their changes with the best methods currently available; n validate and evaluate satellite- based estimates of the surface radiative fluxes; and n verify the results of global climate models (GCMs). The BSRN/WRMC started in 1992 with nine stations. By November 2011, more than 6,000 station-months of data from 54 stations all over the world were available in the archive (see www.bsrn.awi.de/). Although the WRMC was originally designed especially for the needs of climate researchers, the archive is being used more and more in the context of research into solar energy.

Currently active and planned BSRN stations (November 2011)

88 5 International data centres Qualitative tendencies in incoming surface solar radiation in various regions of the world

Region 1990 to 1999 2000 to 2005

USA

Central America

Europe

China/Mongolia

Japan

Korea

India

Antarctica

Source: Wild et al., 2009

International context The BSRN/WRMC was initiated by the World Climate Research Pro- gramme (WCRP). It is affiliated to the Radiation Panel of the WCRP’s Global Energy and Water Cycle Experiment (GEWEX) and is part of GCOS. In 2011, the BSRN/WRMC and the Network for the Detection of Required resources Atmospheric Composition Change In order to ensure effective operation (NDACC, see www.ndacc.org) for- of the WRMC at the Alfred Wegener mally agreed to form a co-operative Institute, Helmholtz Centre for Polar network. To ensure the close co- and Marine Research (AWI), in Bre- operation between the scientists at merhaven, about two scientists and the 54 BSRN stations and the cus- one data curator are needed. Add- tomers of BSRN data, a joint meet- itionally, technical support from the ing takes place every second year. AWI computing centre and from experts of PANGAEA® (Data Publisher for Earth & Environmental Science, see www.pangaea.de) and MARUM (Center for Marine Environmental Sciences, www.marum.de/en/) is indispensable. At the moment, the AWI carries all the corresponding costs.

http://www.bsrn.awi.de http://www.ndacc.org http://www.pangaea.de http://www.marum.de

89 5.4 The World Data Center for Climate at the German Climate Computing Centre

The World Data Center for Climate (WDC-Climate) is maintained by the German Climate Computing Centre (DKRZ), whose mission is to provide users from the climate research community in Germany with access to high- performance computing and technical support. Emphasis is placed on data from climate model calculations, but corresponding observational data from a variety of projects are also available.

High-performance mass storage system s at the DKRZ

Overview of DKRZ data pool

Project Coverage Data type Significance for GCOS The WDC-Climate collects, archives and disseminates climate (model) Caribic B Flight routes between Frankfurt Upper atmosphere variables and the Caribbean 1997 to 2002 data and products and provides these free of charge to the international CCLM M Europe 2001 to 2100 Numerous variables on a 20-km grid, research community. With a view to monthly means and hourly data establishing a well organised network CMIP5 M Global data for model comparisons Numerous variables of data centres for earth sciences, from various time periods from international centres there is close co-operation with ECMWF M Global 1957 to the present day Numerous variables numerous institutions dedicated to reanalyses with up to 80-km resolution related branches of study, such as (ERA) earth observation, meteorology, REMO-UBA M Germany 2001 to 2100 Numerous variables on a 10-km grid, monthly means and hourly data oceanography, paleo-climatology and environmental research. s Blizzard high-performance computer at the DKRZ Photo: DKRZ

90 5 International data centres Mean temperature increase until 2090

s Temperature increase between 1986–2005 and 2090 for scenario RCP 8.5 of the Fifth Assessment Report of IPCC, model MPI-ESM-LR Source: DKRZ

International context Although the WDC-Climate has an international orientation and is open to scientists from all over the world, Model data include global as most data are accessed from the well as continental and national research community in Germany. data sets (see table). Disk storage Here, co-operation with universities capacity of 1,500 terabytes is avail- and major research centres and with able plus more than 100 petabytes institutes of the Max Planck Society on magnetic tapes. or the Deutscher Wetterdienst (DWD) During recent years, data life is equally important. International cycle management has become co-operation also exists for the util- more and more important. This in- isation of data for the preparation of cludes advising the project partners the assessment reports of the Inter- during proposal-writing as well as governmental Panel on Climate Required resources during the lifetime of the project Change (IPCC). The WDC-Climate, The shareholders of DKRZ are the and the concluding data publication which is situated in Hamburg, is Max Planck Society and the Land and dissemination phase, and on involved as part of the IPCC’s Data Hamburg (University of Hamburg) as long-term archival of results. These Distribution Centre (DDC). It is one well as the Alfred Wegener Institute, long-term archived data can be of the internationally leading data Helmholtz Centre for Polar and Marine marked with persistent digital object centres providing data for model Research (AWI) and the Helmholtz- identifiers (DOI), which allow users comparison projects (e.g. CMIP5). Zentrum Geesthacht Centre for to quickly locate the data even after In addition, software solutions from Materials and Coastal Research (HZG). several years. user interfaces to storage of data Financial support is also provided by sets on magnetic tapes are jointly the Federal Ministry of Education developed in international collabor- and Research (BMBF) for the procure- ations. ment of the large-scale technology.

http://www.dkrz.de

91 5.5 The World Data Center for Remote Sensing of the Atmosphere

Since 2003, the World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT) has been hosted and operated by the German Remote Sensing Data Centre (DFD) at the German Aerospace Center (DLR) under the auspices of both the World Meteorological Organization (WMO) and the non-governmental International Council for Science (ICSU). An external advisory board with experts from space agencies such as the European Space Agency (ESA), national meteorological services such as the Deutscher Wetterdienst (DWD) and scientific community bodies, such as the DLR and the Helmholtz Association of German Research Centers (HGF), was established in 2006 to help the WDC-RSAT to achieve its mission goals and serve user requirements. Currently, this advisory board is being extended to also include representatives from EUMETSAT, NASA and WMO.

Significance for GCOS Service for the scientific shop that gives access to space- The WDC-RSAT offers, not just to community borne observations of the chemical scientists but also to the public, The WDC-RSAT is the most recent composition of the atmosphere, at simple and free access to a continu- member in the WMO system of first, however, with a focus on a ally growing collection of satellite- world data centres. Particularly in limited number of parameters, par- based data of the atmosphere and the context of the IGACO1) within the ticularly those concerning ozone and related products and services. WMO’s Global Atmosphere Watch aerosols. This is achieved by either The data products are available programme (GAW) and in line with direct access to the centre’s data online and include raw data as well the GAW strategy plan 2008–2015, collection or indirectly by a portal of as higher level value-added products. it is concerned with linking different links to relevant satellite data and The current WDC-RSAT data-base GAW-relevant data sets with each data products of other providers. provides information on trace gases, other and with model data. In this Following the recommendations of aerosols, clouds, land and sea sur- context, the WDC-RSAT not only the Committee on Earth Observation face parameters and solar radiation. handles satellite data but also data Satellites (CEOS), the WDC-RSAT is from other sources that are import- currently developing an Atmospheric ant for validation purposes. Add- Composition Portal (ACP2)) in co-oper- itionally, strategies and techniques ation with the National Aeronautics are being developed and tested for and Space Administration (NASA), this validation, taking account of, which will eventually be integrated among other things, different assimi- into the Global Earth Observation 1) Integrated Global Atmospheric Chemistry lation methodologies. The data centre System of Systems (GEOSS). Simi- Observations (IGACO) is also addressing the variability lar co-operation is planned with 2) http://wdc.dlr.de/acp of the atmosphere at different time the French Space Agency (CNES) 3) http://wdc.dlr.de/ndmc and space scales (‘miss-integration and the French National Center for 4) http://www.schneefernerhaus.de error’). It operates as a one-stop Scientific Research (CNRS). The

92 5 International data centres Trend of the size of the ozone hole for the years 2007 to 2011 (106 km2)

s The area is derived by assimilating the total ozone concentrations from Metop/GOME2 measurements using the ROSE/DLR chemical transport model. The size of the ozone hole is defined as the area where the total ozone concentration is below 220 Dobson units. Sources: WDC, EUMETSAT, DLR

International context the WDC-Climate (hosted by the The World Data Center for Remote German Climate Computing Centre, Sensing of the Atmosphere is part of DKRZ) or by the Publishing Network the ICSU-WDC family and is there- for Geoscientific & Environmental fore closely linked to all other world Data PANGAEA® (operated by the data centres. Further, the develop- Alfred Wegener Institute (AWI) and ment of a sub-network of WDCs, the University of Bremen, see Chap- WDC-RSAT is designated to play which will focus on relevant aspects ter 5.7). In 2004, the four German an important role within the of the earth system, will lead to ICSU WDCs (Climate, Mare, Terra recently established international increased synergy between the vari- and RSAT) established the WDC- and global Network for the ous data providing bodies. Such a Cluster on Earth System Research to Detection of Mesopause Change co-ordinated approach, in which promote interdisciplinary research (NDMC3)). For this, international WDC-RSAT is involved, aims to give related to earth sciences. co-operation with scientific groups answers to questions on climate The WDC-RSAT also co-operates actively investigating the meso- change and weather extremes. This with various partners in the field of pause region (in ~80–100 km alti- is of basic importance for economic information technology (e.g. Grid) tude) will be supported to detect well-being and the understanding of to improve the networking between long-term trends in airglow. The both natural and man-made causes providers and users. Remote sensing centre will also serve as a com- of climate variability. A large amount data sets and products now each munication and data management of data is necessary to describe the have a digital object identifier (DOI) platform for ground-based meas- climate system and how it is changing, and can be unambiguously and effect- urements from around the world. because it is determined by condi- ively referenced and cited in scien- In addition, the WDC-RSAT sup- tions and changes in the atmosphere tific publications. The WDC-RSAT ports the data management of the and surface parameters of land and has also been designated as a Data German environmental research ocean. Much of the needed data are Collection and Production Center station Schneefernerhaus (UFS4)) collected and archived by four ICSU (DCPC) within the WMO Information on Zugspitze (2,650 m a. s. l.), world data centres, amongst others System (WIS). which is also a GAW station. It is planned to establish a virtual association between the research station and the Norwegian http://wdc.dlr.de/ ALOMAR observatory.

93 5.6 The Global Fire Monitoring Center

The Global Fire Monitoring Center (GFMC) provides a global archive and portal for documentation and information about vegetation fires, including information on early warning and monitoring. National and global metadata about vegetation fires are compiled through an international network of co- operating institutions and are publicly accessible on the Internet.

Significance for GCOS Vegetation fires represent an essential climate variable and influence other climate variables, e.g. the composition of the atmosphere, by gas- Global measurements eous and particle emissions (radiation budget, cloud formation and precipitation). Terrestrial variables directly influenced by fire include, amongst others, hydrological regime, albedo and terrestrial biomass and carbon pools. Examples of indirectly impacted variables include ice and snow cover (by deposition of emitted black carbon) and permafrost regimes (through the modification of vegetation cover). However, fires also have a long-term stabilizing influence on natural and anthropogenic fire-adapted or fire- dependent ecosystems. The most important cause of vegetation fires is the application of fire in traditional land-use systems and for land-use changes. An understanding of the complex interactions between fire, biosphere and atmosphere and their consequences for the climate system are a prerequisite for the definition and interpretation of earth observations within the GCOS framework.

Global Wildland Fire Network of the United Nations Office for Disaster Risk Reduction (UNISDR)

94 5 International data centres Total carbon emissions from vegetation fires from 1960 to 2000

s Time series and regional contributions of total direct carbon emissions from vegetation fires from 1960 to 2000 Source: RETRO Model, Schultz et al., 2008

International context and others) and is an Associate The GFMC is involved in a number Institute of the United Nations of natural and social sciences University. The GFMC is co-chair of research projects and programmes. the Fire Implementation Team of A key mission of the GFMC is the Global Observation of Forest and application of scientific knowledge Land Cover Dynamics (GOFC-GOLD) for the purposes of administration and its ‘Implementation of a Fire and policy. This is achieved by direct Warning System at Global Level’ co-operation with national stake- project (GEO Task DI-09-03B). holders and international organisations whose task it is, through legal provisions and development of international agreements as well as by taking account of global processes, to enable countries to deal with the climate variable fire in order to Required resources avoid the destructive effects of fire Basic institutional funding of the and co-ordinate the use of natural GFMC through the Max Planck Insti- fire and sustainable prescribed fire tute for Chemistry is secured until practices. The GFMC has taken a October 2014. The continuation of the leading role and some functions of GFMC’s work beyond 2014 is not yet relevant thematic working groups in secured. An urgent solution is needed the UN system (UNISDR Global to secure the continuation and expan- Wildland Fire Network and Wildland sion of the application of scientific Fire Advisory Group; UNECE/FAO knowledge. A cross-sector embedding Team of Specialists on Forest Fire, in the UN system would be preferred.

http://www.fire.uni-freiburg.de

95 5.7 The ICSU World Data Centre PANGAEA®

The ICSU World Data Center PANGAEA® – Data Publisher for Earth & Environmental Science (the former WDC-Mare) is a facility for the acquisition, processing, long-term storage and publication of geo-referenced data related to earth science fields. PANGAEA® currently holds around 500,000 data sets comprising 6.5 billion data items from all earth environments.

Significance for GCOS International context PANGAEA® holds an extensive col- PANGAEA® is part of the ICSU World lection of climate-related data, mak- Data System, holding the position of ing it a valuable partner for climate Vice-Chair in the Scientific Committee. research. As a designated data Since the 5th European Framework archive of both the International Programme, PANGAEA® has been Council for Science (ICSU) and the partner in more than 120 mainly high- World Meteorological Organization level projects at global, EU and (WMO), PANGAEA® supports the national scales covering all fields of free and unrestricted availability and environmental sciences (see www. distribution of climate-related data pangaea.de/projects/). Long-standing according to the ICSU’s rules for collaboration exists with the Inte- World Data Centers (WDCs) while at grated Ocean Drilling Program (IODP). the same time protecting intellectual Co-operation with science publishers property by consequently using (Elsevier, Springer, Wiley, Oxford, AGU digital object identifiers (DOI) when and Nature) has been established publishing the data. and extended.

96 5 International data centres Global clay mineral distribution in surface sediments of the Atlantic (in %)

s Source: adapted from Biscaye (1964) and Petschick et al. (1996), doi:10.1594/PANGAEA.55955

Publication series ‘WDC-Mare Reports’ Required resources t PANGAEA® is operated jointly by the Center for Marine Environmental Sciences (MARUM) in Bremen and the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), in Bremerhaven. The two partners provide together four full-time positions for one data librarian, two data curators and one system manager. Eight additional data curators and three software engineers are funded by third parties. Further funding comes from the European Commission (EC), the Fed- eral Ministry of Education and Research (BMBF), the German Research Foun- dation (DFG) and the International Ocean Drilling Program (IODP).

http://www.pangaea.de

97 5.8 Data quality assurance centres of GCOS s Launch of a balloon with several radiosondes during a comparison study

s GCOS Surface Network in 2012

GCOS Surface Network (GSN) forecasting. However, coarse net- With the aim of improving the The GCOS Surface Network (GSN) work density limits the applicability quality and availability of the data is a subset of the Regional Basic of the GSN to a restricted range of from the GSN and the GCOS Climatological Network (RBCN) that climate data products (gosic.org/ Upper-air Network (GUAN), nine collects monthly world climate data content/purpose-gsn). CBS Lead Centres for GCOS were (CLIMAT reports) from the lower In 1999, two GCOS Surface Net- designated by the World Meteoro- atmosphere near the earth’s surface work Monitoring Centres (GSNMC) logical Organization‘s (WMO) Com- and publishes it shortly after the end were set up to oversee the permission for Basic Systems (CBS) in of each month. GSN consists of formance of the GSN, one at the 2006/2007. Their principal task is to more than 1,000 land surface obser- Deutscher Wetterdienst (DWD) and liaise with the National Focal Points vation stations and stations on mid- the other at the Japan Meteoro- for GCOS to bring problems that oceanic islands. These were selected logical Agency (JMA). These moni- have been detected in their areas according to strict criteria, including tor the availability, timeliness and of responsibility to the attention of length and quality of the time series, formal accuracy of inputs from the National Meteorological and geographical representativeness of GSN stations, and check the data Hydrological Services (NMHSs) the observations and range of avail- provided on mean monthly tem- (www.wmo.ch/pages/prog/gcos/ able parameters. A high degree of perature, mean monthly maximum index.php?name=CBSLeadCentres). commitment is expected from GSN and minimum temperatures (JMA) The DWD is responsible for Europe stations with regard to the continuity and monthly precipitation (Global (WMO Region RA VI). In 2011, of observations and the quality of Precipitation Climatology Centre, following the decisions by GCOS’ the monthly data reports. GSN data GPCC). A range of monitoring pro- Atmospheric Observation Panel for provide a basis for assessing climate ducts and the monthly climate data Climate (AOPC) and the Executive variability and climate change, as can be accessed at www.gsnmc. Council of WMO, the responsibility well as for climate modelling and dwd.de. of the CBS Lead Centres will be

98 5 International data centres The GCOS Reference Upper-Air GRUAN and co-ordinate the establish- Network (GRUAN) ment of the network. Two additional The GCOS Reference Upper Air scientist positions were created at Network (GRUAN) is the reference the DWD to support this effort. The network for observations of essential Lead Center plays a central role in climate variables in the free atmos- the definition and realisation of phere. The GRUAN stations conduct reference observations, co-ordinates vertically resolved measurements of the flow of data from the stations the parameters temperature, atmos- and assures that all metadata, which pheric water vapour, wind and pres- are essential attributes of the meas- sure. GRUAN currently consists of urements, are included. Complete 15 stations worldwide, with plans for metadata descriptions of the data expansion to about 30 to 40 stations. series as well as storage of all raw GRUAN stations provide data at the data guarantee that current data will highest quality standards to be used be comparable in the future and that for the purposes of long-term climate observations are homogeneous observation, validation of satellite across the network. This extensive observations and the study of atmos- storage also guarantees that new pheric processes. This goal is insights into data analysis can be achieved through an explicit quanti- applied to the older data. The Lead fication of measurement uncertainty Center provides regular reports and as well as through well-defined updated information about GRUAN operational requirements. at www.gruan.org. The reference status of GRUAN The GRUAN Lead Center co- is achieved through traceability of operates closely with relevant com- measurements to SI units or inter- mittees of the World Meteorological nationally accepted standards. Regu- Organization (WMO), such as the lar redundant measurements and Commission for Instruments and additional ground checks guarantee Methods of Observation (CIMO), the that the measurement error, ana- Commission for Basic Systems (CBS) lysed along with the measurements and the Commission for Atmospheric themselves, are internally consistent. Sciences (CAS), as well as with a Key components are a detailed number of other national meteoro- analysis of systematic and random logical services and universities to measurement errors starting from improve observations at sites that raw data and transparent processing. are not directly connected to GRUAN. extended to include all stations The GRUAN Lead Center was set Furthermore, the Lead Center partici- in the RBCN. All CLIMAT data up in 2008 at the Lindenberg Meteoro- pates in international radiosonde exchanged worldwide will be logical Observatory – Richard Ass- comparison events and conducts checked, completed and archived mann Observatory of the Deutscher independent tests and laboratory by the DWD. Wetterdienst (DWD) to implement experiments on sounding equipment.

Current and planned BSRN stations (as of September 2012) Source: AWI

www.gsnmc.dwd.de www.gruan.org

99 5.9 The Satellite Application Facility on Climate Monitoring

Concerns about the changing global climate have highlighted the need for further development of climate monitoring activities at regional and global levels. To this end, only satellite-based observations provide the necessary geographical coverage of timely, high-quality data. Especially over the oceans and in sparsely populated areas, satellites are generally the only source of data. The aim of the Satellite Application Facility on Climate Monitoring (CM SAF) is to provide the satellite-based geophysical data sets that are required for climate monitoring. The CM SAF is part of the network of Satellite Application Facilities (SAF), which in turn forms an integral part of the Application Ground Segment of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).

Significance for GCOS Organisation The CM SAF provides a range of The CM SAF is part of the SAF net- climatological parameters address- work of EUMETSAT, which consists ing some of the ‘Essential Climate of eight competence centres, each Variables’ (ECV) called for by the one dedicated to a specific scientific GCOS Implementation Plan in sup- question. The operations and further port of the United Nations Frame- development of the CM SAF are led work Convention on Climate Change by the Deutscher Wetterdienst (DWD) (UNFCCC). According to GCOS’ in collaboration with the Royal second report on the adequacy of Meteorological Institute of Belgium the global observing systems for (RMI), the Finnish Meteorological climate, the CM SAF focuses on the Institute (FMI), the Royal Netherlands s provision of geophysical parameters Meteorological Institute (KNMI), the Dark blue: CM SAF Consortium: DWD, Germany describing elements of the energy Swedish Meteorological and Hydro- (leader); FMI, Finland; KNMI, Netherlands; and water cycle, in compliance as far logical Institute (SMHI) and the Swiss MeteoSwiss, Switzerland; Met Office, United as possible with GCOS Climate Federal Office of Meteorology and Kingdom (entry 2012); RMI, Belgium; SMHI, Monitoring Principles. The CM SAF Climatology (MeteoSwiss). The UK’s Sweden provides regional products with a Met Office joined the CM SAF at the Light blue: other EUMETSAT Member and comparatively high spatial resolution beginning of the current project Co-operating States as well as global products that phase in March 2012. complement ongoing international activities.

100 5 International data centres Mean precipitation totals according to the HOAPS-3 data set (mm/d)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec (mm/d) 0 1 2 3 4 5 6 7 8 9 10 s Mean precipitation totals (mm/d) for the period 1981 to 2008 (left: global distribution; right: zonal mean annual cycle)

n macro and microphysical cloud properties n surface radiation parameters, including surface albedo n top-of-the-atmosphere radiation parameters n water vapour and temperature An example of these is the Hamburg Products and services Ocean Atmosphere Parameters and International context The CM SAF provides geophysical Fluxes from Satellite Data (HOAPS) The products and procedures of the data sets for climate monitoring, climate data record (see graph). This CM SAF not only respond to the deriving from measurements by data set of ocean parameters derived aims of GCOS, but also contribute different instruments on geosta- from passive Special Sensor Micro- to other international programmes tionary and polar-orbiting meteoro- wave Imager (SSM/I) measurements such as the World Climate Pro- logical satellites. The data products for the period 1987 to 2008 enables gramme (WCP) and the World Cli- of the CM SAF include monitoring climate studies into ice-free oceans. mate Research Programme (WCRP). data obtained in near real time and The CM SAF offers all its prod- CM SAF data are essential for activ- long-term data sets based on care- ucts free of charge to the scientific ities of the Group on Earth Obser- fully calibrated inter-sensor radi- community, including comprehen- vations (GEO) and the Global Moni- ances. The homogenous sets of sive documentation and information toring for Environment and Security high-quality data help scientists to about validation. User services are (GMES) programme. The DWD also investigate climate variability and provided through the website at participates in European activities its long-term changes. www.cmsaf.eu. Access to available such as the ESA Climate Change The CM SAF’s expanding prod- CM SAF data is provided by an Initiative and various EU-funded uct suite is designed to address online order platform that makes it projects (e.g. EURO4M) that inter- applications focussing on the earth’s easy for users to identify the prod- face with CM SAF. atmospheric water and energy ucts, data and additional services cycles at both global and regional they need for a selected region of scales, including: interest (see wui.cmsaf.eu).

http://cmsaf.eu

101 6.1 Ozone soundings at Neumayer station in the Antarctic

Since 1992, weekly ozone soundings have been performed at the German Antarctic research station Neumayer. The project is ongoing. It continues the time series started in 1985 at the neighbouring German Georg Forster research station. Combined together, the two data sets form the longest time series of ozone soundings in the Antarctic and clearly show the development of the ozone hole.

Significance for GCOS The ozone hole over the Antarctic was discovered in 1985. The sup- position that chlorofluorocarbons (CFCs) from refrigerators and spray cans damage the ozone layer had been a subject of discussion among experts for a long time. However, the first measurable decline in the ozone layer was detected over the Antarc- tic of all places – far away from all anthropogenic CFC sources on the earth. s This discovery turned out to be Time-altitude section of ozone partial pressure of great significance far beyond Ant- above the Antarctic Georg Forster and arctica since it led to the Montreal Neumayer research stations. The ozone layer Protocol in 1987, in which the signa- lies at altitudes between 10,000 and 25,000 m, tory states agreed to the complete identifiable by the high ozone values shown elimination of ozone-depleting sub- in yellow and red. During the Antarctic spring stances. Worldwide CFC production between September and November, the ozone is now almost at an end and the layer regularly weakens, displaying local regeneration of the ozone layer is minimum values in some years (blue) instead expected to take place within the of maximum values (red). coming decades. Source: Gert König-Langlo

http://www.awi.de/en/go/meteorological_observatories

102 6 Observations abroad Time series of seasonal averaged stratospheric parameters (at 70 hPa)

s Time series of average ozone partial pressure (red) and temperature (blue) from September to October at 15 to 18 km above the Georg Forster and Neumayer stations Source: Gert König-Langlo

Ozone altitude profiles above Neumayer station

s Neumayer station (70°40’S, 008°16’W) on the Ekström Shelf Ice (Antarctica) shortly after the rebuilding was finished in 2009. On top of the station, the balloon-filling hall can be seen.

Required resources The Alfred Wegener Institute, Helm- holtz Centre for Polar and Marine Research (AWI) in Bremerhaven runs the Antarctic Neumayer research station including its meteorological observatory and ozone-sounding programme (see www.awi.de/en/ s go/meteorological_observatories). The dramatic ozone destruction in the Antarctic The station was rebuilt in 2009. It spring led to the complete depletion of the has a design life of approximately ozone layer in October 2006. three decades. The ozone-sounding Source: Gert König-Langlo programme is ongoing. The AWI carries all necessary costs.

http://www.awi.de/en/go/meteorological_observatories

103 6.2 Glacier monitoring abroad

The Glaciology department of the Commission for Geodesy and Glaciology (KEG) of the Bavarian Academy of Sciences and Humanities (BAdW) has determined the changes in area of ten Austrian glaciers since 1889 at 10-year intervals. In addition, the annual sums of mass balance for the Vernagt- ferner Glacier in the Ötztal Valley have been analysed since 1964 and hourly values of the total glacier discharge recorded since 1974.

Description of measurements parts. Measurements of the ice thick- Ten of the fifteen Eastern Alpine ness with geo-radar in 2007 gave a glaciers monitored by the KEG lie in mean value of 31 m. Austria and are predominantly sur- Since 1964, the direct glaciological veyed with the geodetical method. method has been used to determine Four glaciers are in the Ötztal Valley the mass balance of Vernagtferner (Vernagt, Guslar, Hintereis and for the accumulation and ablation Gepatsch), two in the Stubai Valley periods separately (see graph, top (Sulzenau and Grünau) and four in part). The separate analysis of winter the Zillertal Valley (Schwarzenstein, and summer figures shows that the Horn, Waxegg and Schlegeis). The high loss of ice mass does not result longest data series is available for from lower precipitation in winter, Vernagtferner (see graph and meas- but from higher amounts of melting urement description in Chapter 4.6), during summer. The series shows a the second longest series for Hinter- mean total loss of 16.2 m water equi- eisferner (going back to 1894). valent for the period 1964 to 2010, Gepatschferner and all the glaciers with the highest losses in 2003. in Zillertal Valley have been moni- In 1973, the Vernagtbach gauge tored since 1921, the Stubai glaciers and climate station was installed since 1932. All series of changes in which, at 2,640 m, is the highest dis- mass show a similar time pattern, charge measuring point in the East- with high losses until around 1950, ern Alps. The station is unmanned, slight gains between 1960 and 1980 with monthly maintenance controls and finally even higher losses than between April and November. in the first half of the century. The Between 1974 and the mid-1980s, mean loss in thickness of Vernagt- meteorological and hydrological ferner between 1889 and 1969 was parameters were recorded mainly about 30 cm/a, with a loss in area during the summer, but measure- from 11.58 km2 to 9.56 km2. In 2009, ments have been carried out prac- the total area amounted to 7.92 km2 tically all year for about the last and the glacier had split into two 25 years. The data include hourly

104 6 Observations abroad Annual mass balances and discharge totals for Vernagtferner

s Photo of the central part of Vernagtferner The figure shows both the annual mass (taken with an automatic camera on balances determined for Vernagtferner in the 17. 08. 2011) Ötztal Valley using the direct glaciological method (top part) since 1964/65 and the annual discharge totals recorded at Vernagtbach gauge station since 1974 (bottom part) (Escher-Vetter, 2011). In addition to the total mass balance (continuous turquoise line), winter and summer balances (blue and red columns respectively) are presented (Escher-Vetter et al., 2009). Linear trends are included for all parameters. values for discharge, precipitation The discharge trend shows an increase from and air temperature, as well as the 1,280 mm to 2,410 mm, a near-doubling of the four radiation components, air pres- total discharge between 1974 and 2010. The sure, air humidity, snow height and increase in the mass balance in summer is various other hydrological param- even greater, with absolute values of around eters. Daily photographs of the glacier -800 mm water equivalent (mm w. e.) in 1964 are available for the summer months and -1,750 mm w.e. at the end of the period. going back to 1976, direct ablation Thus, summer losses due to melting have more measurements on the ice surface than doubled. In contrast, winter mass balance, since 2005. All meteorological and i.e. the amount of precipitation in winter, shows hydrological data sets can be obtained only a slight decline from approx. 1,000 mm free of charge from the PANGAEA® w.e. to 880 mm w.e. database at www.pangaea.de.

Required resources Due to the uncertainty surrounding the financing of the KEG after 2015 (see Chapter 4.6) future monitoring of the Vernagt Glacier is greatly endangered. In addition, the amount of data collected during the last decades is so vast that additional staff is required in order to process all the parameters and publish the results.

http://www.glaziologie.de

105 6.3 International tide gauge observations

For about ten years now, international analysis centres, co-ordinated by the Helmholtz Centre Potsdam – German Research Centre for Geosciences (GFZ), have been evaluating all freely available GPS measurements taken by tide gauges and referenced to tide gauge zero. In the framework of the Tide Gauge Benchmark Monitoring project (TIGA), co-ordinated by GFZ, results are made available in the form of time series of sea height changes and mean vertical movements.

Description of measurements sidence. The development of space- In the history of the earth, the sea based geodetic monitoring tech- level has oscillated in response to niques, such as GPS, has enabled the climate fluctuations between warm vertical movement of coastal gauges and cold periods by up to 200 m. to be tracked systematically using Although sea level height has new, cost-effective methods, and be remained fairly constant during the taken into account in the analyses. last 2,000 years, it has risen globally Since the beginning of the 1990s, since the middle of the 19th century. international organisations, including Before the introduction of the first the International GNSS Service (IGS), satellite-based radar altimeters in the the Permanent Service for Mean Sea 1980s, coastal gauges were generally Level (PSMSL), UNESCO’s Global used to monitor changes in sea level. Sea Level Observing System (GLOSS) The first systematic tide gauge meas- and number of other research insti- urements were conducted by the Royal tutes, have defined the scope and Society of London after 1660; continu- aims of an international service for ous time series have been available correction of the vertical movement for about 150 years. However, estim- of coastal gauges. In this work, ation of the sea level rise from these Global Navigation Satellite System measurements is problematic, since (GNSS) techniques, i.e. GPS, the gauges themselves can move in GALILEO and GLONASS, will have relation to sea level as a result of pro- a particularly important role to play. cesses such as land uplift and sub- At the 7th session of the IOC/GLOSS Group of Experts in 2001, the GFZ presented a draft project to set up a pilot service (the TIGA project) to operate under the auspices of the IGS. Since then, international analysis centres, co-ordinated by GFZ, have been evaluating all freely available GPS measurements continuously taken by tide gauges and referenced to the tide gauge zero. In the framework of the GFZ-co-ordin- s ated TIGA project results are made Network of GPS stations at tide gauges available in the form of time series of (green triangle: TIGA observing stations; sea height changes and mean vertical red star: stations in the test phase) movements.

106 6 Observations abroad Mean monthly sea level (mm)

An example of the effects of the correction for vertical land movement is the gauge in Charleston (South Carolina, USA). The gauge data, recorded over a period of almost a century, show an upward trend, which takes a slightly negative turn if the vertical movement rate (assumed to be constant in the past) is determined and corrected by GPS. Graphic: Nana Schön, GFZ

The goals and tasks of TIGA can be ence system, stable over the long summarised as follows: term, to improve the accuracy of 1. Provision of high-quality data to the vertical components. To this calculate GNSS station coordinates end, parts of the IGS network will and velocities at or near coastal be reanalysed in addition to the gauges. The analyses are regularly repeated analyses within the TIGA repeated using the latest methods network. The results of the analysis and models and incorporating all currently under way will be newly available station data. published in 2013. 2. Maintenance of the global network of GNSS stations at tide gauges Significance for GCOS n monitoring the existing network Three German institutes take part in of GNSS stations at tide gauges, the work of the TIGA project: the and densification and expansion German Federal Agency for Carto- of the network, especially in the graphy and Geodesy (BKG), which southern hemisphere; combines the results of the European n analysis of GNSS data streams Geodetic Reference Frame (EUREF) with different latencies; network, the German Geodetic n support for initiatives to increase Research Institute (DGFI) and the network density by integrating GFZ. The results made available continuously operating GNSS internationally over the past years stations into the TIGA network; through the work of TIGA and its n linking up the TIGA network analysis centres have given rise to based on GNSS stations with and provided support for numerous stations that use other methods studies. The latest studies show, for to determine vertical movements, example, a high degree of consist- such as Doppler Orbitography ency among GPS-corrected estimates and Radiopositioning Integrated of the trend of sea level rise. The by Satellite (DORIS) stations, analyses of the TIGA project have Satellite Laser Ranging (SLR) also contributed to methodological stations and stations that are improvements in mathematical connected through relative or reconstructions of sea level trends absolute gravity measurements. and variations over the last decades, 3. Investigations leading to the and in the calibration of satellite- implementation of a global refer- based radar altimeters.

http://adsc.gfz-potsdam.de/tiga/

107 6.4 CO2 partial pressure in the ocean

Observation of marine carbon circulation is one of the most important tasks of marine research (Riebesell et al., 2009; Gruber et al., 2010). The focus of attention is the take-up and storage of anthropogenic CO2, climate-driven changes in the natural carbon cycle and the effects of CO2 take-up on the marine ecosystem (ocean acidification).

Description of measurements the GEOMAR Helmholtz Centre for The observations required to provide Ocean Research in Kiel. answers to scientific and social n Baltic VOS line between Germany questions raised by these issues and Finland: this line, which was exceed the capacity of a single moni- initiated in 2003, is operated by toring system. A network of harmon- the Leibniz Institute for Baltic Sea ised and co-ordinated observations Research, Warnemünde (IOW) and is required. The most important is part of the institute’s long-term components of this co-ordinated monitoring programme. It has a effort include the following: strong trace gases component. n a network of commercial vessels n Polarstern VOS line: following the

operating as voluntary observing installation of an automated pCO2 ships (VOS) which provide con- measurement system on the 3. Hydrographic research cruises: tinuous autonomous measure- research ship Polarstern, autono- n Germany has undertaken hydro-

ments of CO2 partial pressure mous measurements are routinely graphic sections in the Weddell (pCO2) and other relevant sea conducted during research cruises. Sea (e.g. SO2, SO4) and in the surface para-meters; 2. Time-series stations: subpolar North Atlantic (A01, A02) n a network of oceanic time-series n Cape Verde Ocean Observatory and plans to continue to partici- stations in key regions (Send et al., (CVOO): this oceanic time-series pate in this activity on a limited 2010); station, situated off the Cape basis. n an international programme of Verde Islands, formerly known Alongside the data portals that are regular sampling of selected as Tropical Eastern North Atlantic operated by single research insti- hydrographic sections (Repeat Time Series Observatory tutes, the collected data are stored Hydrography Program) (Hood (TENATSO) and part of the Euro- and made available in the inter- et al., 2010) SITES network (www.eurosites. national PANGAEA® data bank, Germany makes an important con- info), represents a significant jointly operated by AWI and the tribution to all three network com- extension of the international Center for Marine Environmental ponents through its participation in monitoring network. Science (MARUM). n the international monitoring system Hausgarten Observatory: in the The collected data on CO2 are co-ordinated by the International framework of ICOS-D (the German also passed on to the international Ocean Carbon Coordination Project contribution to ICOS), the Alfred data banks operated by the Surface

(IOCCP). Wegener Institute, Helmholtz Ocean CO2 Atlas (SOCAT), the 1. VOS network: Centre for Polar and Marine Carbon Dioxide Information Analysis n Transatlantic VOS line between Research (AWI), in collaboration Center (CDIAC) and the CARbon Europe and North America: this with GEOMAR, intends to upgrade Dioxide IN the Atlantic Ocean VOS line crossing the subpolar the Hausgarten long-term (CARINA) project.

North Atlantic was incorporated in monitoring station and include a Measurements of pCO2 in near- 2002 and has been operated since sea surface CO2 monitoring surface ocean water have been then with some interruptions by component. undertaken sporadically since the

http://www.icos-infrastructure.eu

108 6 Observations abroad Present VOS network for measurement of pCO2 at the sea surface

s Continuous, autonomous measurement of

partial pressure of CO2 (pCO2) and other relevant sea surface parameters by voluntary observing ships (VOS) Source: adapted from Monteiro et al., 2010; Watson et al., 2008

end of the 1960s; today, measure- Legal framework ments are assured through the At present, there is no legal obli- international VOS network that has gation to monitor the carbon cycle; developed since the 1990s, and however, it is regulated by inter- above all in the last decade. The national agreements. famous, periodically updated pCO2 Required resources climatology of Taro Takahashi Measurement of CO2 on the three (Takahashi et al., 1995, 1997, 2002, above-mentioned VOS lines (sub- 2008) was based on this data set. polar North Atlantic, Baltic Sea, Artic/

The Surface Ocean CO2 Atlas Antartic) and at the two long-term (SOCAT), which has been under monitoring stations in the tropics construction since 2007, currently (CVOO) and the Arctic (Hausgarten) represents the largest global data are currently financed by the Federal series, incorporating to date a total Ministry of Education and Research of 6.7 million measurements from (BMBF) within the pilot and demon- 1,851 research cruises undertaken International context stration phase (2012–2013) of the in the period 1968–2007. The activities were, or still are collaborative project ICOS-D, which Long data series from oceanic components of the EU programmes will be followed by a two-year time-series stations are essentially EuroSITES (IP, FP7) and CARBO- implementation phase (2014–2015), limited to the Bermuda Atlantic CHANGE (IP, FP7), and are part of the also BMBF funded. In the long-term, Time-series Study (BATS), the German contribution to ICOS. Inter- it is intended that resources for long- Hawaii Ocean Timeseries (HOT, nationally, they are co-ordinated by term operations should be made ALOHA), and the European Station the IOCCP and the OceanSITES available by the institutions in for Time series in the Ocean at the initiative. charge. Canary Islands (ESTOC) (Bates, 2007; Santana-Casiano et al., 2007; Dore et al., 2009). http://www.socat.info http://cdiac.ornl.gov http://www.go-ship.org http://www.pangaea.de

109 6.5 Deep ocean currents

Ocean currents are important for the distribution of heat, fresh water and matter around the world. Deep ocean currents are driven mainly by horizontal density differences. These currents, and especially the meridional overturning circulation (MOC) that carries warm water northwards and returns cold, deep waters southwards, are key variables and important components of the climate over longer (decadal) time scales. However, deep ocean currents are recorded only in a few selected places and long-term records are extremely rare.

Description of measurements carry out long-term monitoring. Most Measurement of deep ocean cur- of these are equipped with sensors rents by German research groups to record a variety of parameters, focuses on long-term moored obser- including flow-meters for the pro- vation at key locations in the global duction of long-term statistics on ocean circulation system. Measure- velocity fields. ments in the straits between ocean These stations are located in the basins play a central role. In the north, Irminger Sea, the Labrador Sea and the Alfred Wegener Institute, Helm- in the tropics (Cabo Verde), and form holtz Centre for Polar and Marine part of wider national and EU initia- Research (AWI) maintains a mooring tives. In the far southern Ocean, in array in the Fram Strait, where flows the Weddel Sea, the AWI is conduct- between the Arctic Ocean and the ing long-term measurements of cur- European North Sea are recorded. rents in the Weddel Gyre, by means The neighbouring oceanic sill is the of anchored and free-drifting Argo Denmark Strait,where the Institute of floats equipped with a special ice Oceanography of the University of sensing algorithm. Hamburg (IFM Hamburg) has meas- Alongside the anchored systems, ured the overflow for many years. In the currents at 1,000 to 1,500 m depth addition, oceanic boundary currents are measured globally by Argo deep- are measured at all depth layers at water drifting sensors based on various points across the globe. The international initiatives. most well-known arrays include those In the 1990s, the World Ocean measuring outflow from the Labrador Circulation Experiment (WOCE) Sea at 53°N and at the Flemish Cap, recorded and described ocean circu- and, in the tropics, boundary cur- lation patterns under average con- rents and the Equatorial Circulation ditions. Afterwards, the focus shifted (GEOMAR Helmholtz Centre for Ocean more to the variability of climatically Research). Within the ocean basins, relevant parameters, of which ocean a number of observation stations circulation is one. With the focus

110 6 Observations abroad Decadal changes in deep-water parameters in the Labrador Sea

s Top: Deep-water temperature at the Labrador Sea outflow Bottom: Corresponding deep sea currents, showing short-term fluctuations but no discernable trend

International context Studies of long-term fluctuations of the boundary current system and oceanic straits as well as those aimed at the quantification of the MOC are very time-consuming and now on climate and climate vari- expensive. For this reason, ocean ability, exemplified by WOCE’s suc- current monitoring networks are the cessor project Climate Variability subject of international agreements and Predictability (CLIVAR), there and a joint international effort is has been a further shift of emphasis required to install them. German towards measurement of long-term participation is essentially through fluctuations of the climate system. EU programmes – in which national Long time series are essential to collaborative projects funded by the investigate ocean-climate inter- Federal Ministry of Education and Required resources actions, such as weakening of the Research (BMBF) and the German Long times series are the basic MOC, sea-level rise, the provision- Research Foundation (DFG), e.g. in requirement for detection of climate ing of oxygen minimum zones, etc. the form of ship times or Collabora- change on earth; the Keeling Curve The available data are very tive Research Centres (SFB), play a showing the long-term rise in atmos- variable, with respect to the length central role. Data storage and the pheric CO2 concentrations provides a of the records and set of variables timely availability of data records to well-known example. In this respect, recorded by the different stations the international research community the German contribution is important shown in the map. As an example, (e.g. through the OceanSITES initia- and internationally recognised. How- the time series of measurements at tive) are important considerations. ever, the sustainability of the obser- 1,500 m depth by four anchored The definition of standards, quality vations is not secured, and long time floats in the 53°N array (illustration assurance and compatibility of meas- series run the risk of being discon- above) over ten years show a fairly urement data are all particularly tinued at short notice due to financial clear trend in the temperature of important for long-term monitoring constraints. To mitigate this risk a the deep-water current; by contrast, and require international networking new approach is required and suit- breaks in the time series make it through programmes, such as able funding mechanisms need to be impossible to discern a long-term OceanSITES. put in place. trend. This illustrates the need for sustained data collection at key locations in the ocean current system. http://www.clivar.org http://www.awi.de http://www.geomar.de

111

7. Conclusions and outlook

This report is the first to present a truly comprehensive overview of the current state of climate data collection at the regional and national levels in Germany based on long-term data series of the various climate variables. As such, it documents Germany’s contribution to GCOS. The report provides an outline of the legal foundations and points out deficiencies in the sustainability of observation activities (see Table 3 on pages 114 ff.) It thus constitutes an important planning basis for maintaining and further enhancing Germany’s national climate observing system, GCOS-DE.

Conclusions Besides the Essential Climate Varia- The GCOS Implementation Plan sets bles (ECVs) defined for data analysis forth how strongly GCOS as a global at global, regional and national system depends on well-functioning levels, other, locally specific climate components at the national level. parameters may be of additional Through its Resolution 29, the World interest. In Germany, for example, Meteorological Organization (WMO) the variables pollen, isotopes in has therefore urged its Member precipitation and plant phenology States at its 16th Congress (WMO, have been identified as of specific 2011) national interest. In some cases there also exist Europe-wide obser- “[…] vation networks for these additional (1) to strengthen their national variables. atmospheric, oceanographic Not all processes and interactions and terrestrial climate observing in the climate system are known yet. networks and systems, includ- Further to carrying out new, target- ing networks and systems for the oriented studies, the sustainable con- hydrological and carbon cycles tinuity of long-term series of obser- and the cryosphere within the vations is needed to build up a large framework of GCOS and in sup- body of data for research and for port of user needs; further development and enhance- (2) to assist other Members to ment of climate models. This will strengthen their observing net- help to further reduce the uncertain- works; ties about the future of our climate. (3) to ensure, to the extent possible, One of the aims of this report the long-term continuity of the therefore is to enhance the continu- critical space-based components ity of long-term series of observa- of GCOS; tions, especially those for the ECVs. (4) to establish GCOS National Table 3 highlights those areas where Committees and to identify there exists no legal framework for GCOS National Coordinators running climate observations or […].” where no such framework is discern- ible as well as those where the

112

Conclusions and outlook 7 continuity of the observations is not toring Centre (GFMC) requires action secured or the necessary funding is to be taken from 2014 onwards. missing. This classification relies on Alongside the collection of infor- an analysis and assessment carried mation about the state and history of out on the basis of the information the climate system, six areas of action provided by the various expert outside German territory where authors and contributors to this Germany contributes to GCOS activ- report. ities have been defined. With the The observation of most atmos- exception of the observations at the pheric, oceanic and terrestrial ECVS Neumayer station in the Antarctic, (Chapters 2 to 4) has a legal founda- the future of all of these is considered tion. In addition to these, the Federal as ‘not secured’ (see Table 3). The Republic of Germany has to meet its long-term records of atmospheric commitments arising from inter- processes continuously gathered national conventions and treaties, over centuries have proven to be a such as the United Nations Frame- treasure trove of scientific data, work Convention on Climate Change needed for understanding the climate. (UNFCCC), the Kyoto Protocol, the To detect and understand critical Global Earth Observation System of changes, e.g. in connection with Systems (GEOSS), the Global Moni- ocean acidification or the intensity of toring for Environment and Security thermohaline circulation, as early as (GMES) initiative and GCOS. How- possible, we must continue to aim ever, the observations of some ECVs for sustainable observation of all are considered as ‘not secured’. Other ECVs including the oceans and at the activities are only partly secured or ocean surface. secured until a certain date, with great uncertainty regarding their Evaluation continuity. And what adds to this is On the whole, the German GCOS that the data may not be exploited or segment GCOS-DE can be evaluated analysed to their full extent due to as good. This applies to the quality the lack of resources or that there of the data collected just as much as may be large gaps, either of which to the sustainability of the observa- makes climatological analysis of the tion programme – with a few excep- data very difficult. tions. Measures should therefore be However, a large deficiency still taken to sustain all climate observa- exists where sustainable observations prescribed by law, but at the tions of greenhouse gases as key very least the observation of all cli- climate drivers are concerned. For mate variables relevant to Germany this reason, in particular those pro- as described in this report. This grammes should become permanent applies to both in situ and remote under which greenhouse gases are sensing observations and must in- observed both because of their im- clude data analysis as well as quality portance as core parameters for the assurance, data storage and avail- description of the climate system ability and accessibility of the data. and with a view to successful climate In this context, operators of observ- protection. ing systems must report on how As an additional need for data they meet the GCOS Climate Moni- analysis is reported for several of the toring Principles (WMO 2003b, see climate variables, the resources allo- Table 2). cated should be reviewed to ensure Germany also makes valuable optimal exploitation of the data. contributions to GCOS in the fields With the responsibilities for some of international data and product of the climate variables being distrib- centres. These centres provide the uted widely, the compilation of this various application areas with data most comprehensive overview of sets and products that are of the climate observation in Germany highest quality and in many respects required the collaboration of many unique. Most of the international experts and authors. A national data centres can be considered as GCOS programme would facilitate secured. Only the Global Fire Moni- greater transparency, streamlined

113 Climate variable Legal Institution(s) in charge framework

Measurements in Germany Atmospheric observations Near surface 2.1 Temperature exists DWD 2.2 Wind exists DWD 2.3 Air pressure exists DWD 2.4 Precipitation exists DWD 2.5 Radiation exists DWD 2.6 Sunshine duration exists DWD Free atmosphere 2.7 Temperature, wind and exists DWD water vapour 2.8 Clouds exists DWD Atmosphere composition 2.9 Carbon dioxide exists UBA 2.10 Methane exists UBA 2.11 Other greenhouse gases exists UBA 2.12 Ozone exists Länder 2.13 Aerosols exists UBA 2.14 Pollen exists DWD and PID

Ocean observations Sea surface 3.1 Ocean temperature exists BSH 3.2 Salinity exists BSH 3.3 Sea level exists BSH and Länder

3.4 Sea state exists BSH 3.5 Sea ice exists BSH Open ocean 3.6 Deep water formation none Within the framework of basic research at universities and research institutes Ocean composition 3.7 Ocean colour exists BSH 3.8 Nutrients exists BSH and Länder in the ocean 3.9 Oxygen conditions exists BSH and Länder in the North Sea Terrestrial observations Hydrosphere 4.1 Runoff exists BfG and Länder

4.2 Water use exists BfG implementation: Länder 4.3 Groundwater exists BfG implementation: Länder 4.4 Stable isotopes none HMGU, DWD in precipitation Cryosphere 4.5 Snow cover exists DWD 4.6 Glaciers and exists BAdW and LfU permafrost Biosphere 4.7 Albedo exists DWD 4.8 Soil carbon exists Thünen Institute for Forest Ecosystems, the Federation, Länder 4.9 Forest fires exists DWD and Länder 4.10 Soil moisture exists DWD and Länder 4.11 Phenology exists DWD and Länder 114 7 Conclusions and outlook Climate variable Legal Institution(s) in charge Sustainability of observations approaches and co-ordinated imple- Outlook framework (funding) mentation strategies, with the aim of The primary aim should be to secure establishing the German Climate the sustainability and continuity Measurements in Germany Observing System (GCOS-DE) to its of those German climate observa- Atmospheric observations full extent. In agreement with Reso- tions that are of major importance. lution 29 of the 16th WMO Congress Germany’s National GCOS Coordin- Near surface 2.1 Temperature exists DWD largely secured (WMO, 2011), it is therefore planned ator, who is based at the Deutscher 2.2 Wind exists DWD largely secured to establish a steering body for Wetterdienst (DWD), will continue to 2.3 Air pressure exists DWD largely secured GCOS-DE (i.e. a national GCOS com- strive for this goal. To support these 2.4 Precipitation exists DWD largely secured mittee), based on the national GCOS efforts, the establishment of a Nation- meeting. al GCOS Committee for Germany is 2.5 Radiation exists DWD largely secured An overall, Internet-based climate currently being discussed. In this 2.6 Sunshine duration exists DWD largely secured information system that can provide context, special attention is being Free atmosphere 2.7 Temperature, wind and exists DWD largely secured an always up-to-date overview of the paid to respecting the Climate Moni- water vapour state and development of the climate toring Principles of GCOS (see Table 2 2.8 Clouds exists DWD largely secured in Germany, present the findings on page 10) to assure that data are obtained through GCOS-DE and list free from any undesired interference Atmosphere composition 2.9 Carbon dioxide exists UBA partly secured all responsible institutions would be signals. In addition, accurate docu- 2.10 Methane exists UBA partly secured a useful support tool for political and mentation of the metadata must be 2.11 Other greenhouse gases exists UBA not secured economic decision-making and a guaranteed to assure the correct valuable contribution towards imple- assessment of data now and in the 2.12 Ozone exists Länder largely secured menting the Framework Convention future. 2.13 Aerosols exists UBA partly secured on Climate Change. It should there- In addition to in situ observa- 2.14 Pollen exists DWD and PID not secured fore be installed in the medium term. tions, remote sensing-based data (e.g. satellite and radar data) are Ocean observations increasingly used for climatological applications. Provided that GCOS’ Sea surface 3.1 Ocean temperature exists BSH largely secured special principles for satellite-based 3.2 Salinity exists BSH largely secured climate observation are followed 3.3 Sea level exists BSH and Länder largely secured properly, the resulting data are a good complement to in situ data due 3.4 Sea state exists BSH largely secured to the additional information they provide. Satellite data are especially 3.5 Sea ice exists BSH largely secured well suited for filling spatial data Open ocean 3.6 Deep water formation none Within the framework of basic research not secured gaps in global climate observation at universities and research institutes coverage as well as for the deriva- Ocean composition 3.7 Ocean colour exists BSH not secured tion of global data sets (see Table 1; 3.8 Nutrients exists BSH and Länder largely secured WMO, 2006; WMO, 2011). in the ocean The list of ECVs is not static; ad- 3.9 Oxygen conditions exists BSH and Länder largely secured vancing climate research and meas- in the North Sea urement technologies will enable new variables to be added to it. New Terrestrial observations requirements from the users, e.g. in Hydrosphere 4.1 Runoff exists BfG and Länder largely secured the context of the planning of adaptation to climate change, may also 4.2 Water use exists BfG largely secured cause changes to the list. The signifi- implementation: Länder cance of new ECVs for Germany 4.3 Groundwater exists BfG largely secured must be verified and co-ordinated as implementation: Länder part of the implementation of the 4.4 Stable isotopes none HMGU, DWD not secured GCOS Implementation Plan (WMO, in precipitation 2010). The parties to the United Nations Cryosphere 4.5 Snow cover exists DWD largely secured Framework Convention on Climate 4.6 Glaciers and exists BAdW and LfU not secured after 2015 Change have, until the beginning of permafrost Table 3: 2014, to submit their latest report Biosphere 4.7 Albedo exists DWD largely secured Overview of the Essential Climate Variables on their contribution to systematic 4.8 Soil carbon exists Thünen Institute for Forest Ecosystems, partly secured and their status in terms of legal framework, climate observation. On the basis of the Federation, Länder institution(s) in charge and funding these reports, combined with the (in red: measurement series and data centres 5th IPCC Assessment Report, a new 4.9 Forest fires exists DWD and Länder largely secured whose continuity is endangered) review of the adequacy of the Global 4.10 Soil moisture exists DWD and Länder largely secured 4.11 Phenology exists DWD and Länder partly secured 115 Climate variable Legal framework Institution(s) in charge

International data centres 5.1 Global Precipitation Climatology Centre (GPCC) not required* DWD and Länder

5.2 Global Runoff Data Centre (GRDC) not required* BfG

5.3 World Radiation Monitoring Center (WRMC) not required* AWI

5.4 World Data Center for Climate at the German not required* Max Planck Society, Land Hamburg Climate Computing Centre (WDC-Climate) (Hamburg University), AWI, HZG, BMBF 5.5 World Data Center for Remote Sensing not required* DFD, DLR of the Atmosphere (WDC-RSAT) 5.6 Global Fire Monitoring Center (GFMC) not required* Max Planck Institute for Chemistry

5.7 ICSU World Data Center PANGAEA® not required* MARUM, AWI

5.8 Data quality assurance centres of GCOS not required* DWD

5.9 Satellite Application Facility not required* DWD with EUMETSAT on Climate Monitoring (CM SAF) and other partners

*usually by self-commitment of the Federation

Observations abroad 6.1 Ozone soundings at Neumayer station exists AWI in the Antarctic 6.2 Glacier monitoring abroad not required KEG

6.3 International tide gauge observations exists BKG, DGFI, GFZ

6.4 Partial pressure of CO2 in the ocean exists GEOMAR

6.5 Deep ocean currents not required AWI, IFM Hamburg, GEOMAR

116 7 Conclusions and outlook Climate variable Legal framework Institution(s) in charge Sustainability of observations Climate Observing System, GCOS, (funding) will commence to assess its suitabil- ity and coverage. The discovery of any synergies International data centres between the measuring networks 5.1 Global Precipitation Climatology Centre (GPCC) not required* DWD and Länder largely secured could indicate some potential for optimising observation activities and 5.2 Global Runoff Data Centre (GRDC) not required* BfG largely secured help to improve the understanding of the climate system as a whole. In this context, integrated analyses of 5.3 World Radiation Monitoring Center (WRMC) not required* AWI largely secured several climate variables could be valuable. 5.4 World Data Center for Climate at the German not required* Max Planck Society, Land Hamburg largely secured For this reason, a well-functioning Climate Computing Centre (WDC-Climate) (Hamburg University), AWI, HZG, BMBF national climate observation system 5.5 World Data Center for Remote Sensing not required* DFD, DLR largely secured also is an important pillar for national of the Atmosphere (WDC-RSAT) implementation of the Global Frame- 5.6 Global Fire Monitoring Center (GFMC) not required* Max Planck Institute for Chemistry not secured after 2013 work for Climate Services (GFCS).

5.7 ICSU World Data Center PANGAEA® not required* MARUM, AWI largely secured

5.8 Data quality assurance centres of GCOS not required* DWD largely secured

5.9 Satellite Application Facility not required* DWD with EUMETSAT largely secured on Climate Monitoring (CM SAF) and other partners

*usually by self-commitment of the Federation

Observations abroad 6.1 Ozone soundings at Neumayer station exists AWI largely secured in the Antarctic 6.2 Glacier monitoring abroad not required KEG not secured after 2015

Table 3: 6.3 International tide gauge observations exists BKG, DGFI, GFZ not secured Overview of the Essential Climate Variables and their status in terms of legal framework,

6.4 Partial pressure of CO2 in the ocean exists GEOMAR not secured after 2014 institution(s) in charge and funding (in red: measurement series and data centres 6.5 Deep ocean currents not required AWI, IFM Hamburg, GEOMAR not secured whose continuity is endangered)

117 Authors

Ina Abel Lower Saxony Ministry of Food, Agriculture, Consumer Protection and Rural Development; 4.9

Michaela Bach Thünen Institute of Climate-Smart Agriculture; 4.8

Andreas Becker Deutscher Wetterdienst; 2.4, 5.1

Klaus Behrens Deutscher Wetterdienst; 2.5

Séverine Bernoville World Data Center for Remote Sensing of the Atmosphere; 5.5

Michael Bittner World Data Center for Remote Sensing of the Atmosphere; 5.5

Jörg Uwe Belz Federal Institute of Hydrology; 4.1

Ute Dauert Federal Environment Agency; 2.12

Michael Diepenbroek MARUM – Center for Marine Environmental Sciences; 5.7

Anna-Dorothea Ebner von Eschenbach Federal Institute of Hydrology; 4.2

Heidi Escher-Vetter Bavarian Academy of Sciences and Humanities, Commission for Geodesy and Glaciology; 4.6, 6.2

Jürgen Fischer GEOMAR Helmholtz Centre for Ocean Research Kiel; 6.5

Alexander Frohse Federal Maritime and Hydrographic Agency; 3.2

Petra Fuchs Deutscher Wetterdienst; 5.9

Ulrich Görsdorf Deutscher Wetterdienst; 2.8

Johann G. Goldammer Global Fire Monitoring Center; 5.6

Wilfried Hagg Ludwigs-Maximilians-Universität (LMU Munich), Department of Geography; 4.6

Jürgen Holfort Federal Maritime and Hydrographic Agency; 3.5

T. Hanke Lower Saxony Ministry of Food, Agriculture, Consumer Protection and Rural Development; 4.9

Rainer Hollmann Deutscher Wetterdienst; 2.4

Uwe Kaminski Deutscher Wetterdienst; 2.14

Lars Kaleschke Centre for Marine and Atmospheric Sciences; 3.5

Frank Kaspar Deutscher Wetterdienst; 2.1, 2.2, 2.3, 2.6, 4.5

Stefan Kern Federal Maritime and Hydrographic Agency; 3.1

Birgit Klein Federal Maritime and Hydrographic Agency; 3.3

Holger Klein Federal Maritime and Hydrographic Agency; 3.7

Gert König-Langlo Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research; 5.3, 6.1

Arne Körtzinger GEOMAR Helmholtz Centre for Ocean Research Kiel; 6.4

Willi Laier Federal Institute of Hydrology; 4.3

Michael Lautenschlager German Climate Computing Centre; 5.4

118 Annexes List of authors 8

Christine Lefebvre Deutscher Wetterdienst; 5.8

Peter Löwe Federal Maritime and Hydrographic Agency; 3.1

Ulrich Looser Federal Institute of Hydrology/Global Runoff Data Center; 5.2

Hermann Mächel Deutscher Wetterdienst; 2.4

Christoph Mayer Bavarian Academy of Sciences and Humanities/Commission for Geodesy and Glaciology; 6.2

Richard Müller Deutscher Wetterdienst; 4.7

Gerhard Müller-Westermeier Deutscher Wetterdienst; 2.1, 2.2, 2.3, 2.6, 4.5

Christine Polte-Rudolf Deutscher Wetterdienst; 4.11

Andreas von Poschinger Bavarian Environment Agency, Geological Survey; 4.6

Monika Rhein Institute of Environmental Physics, University of Bremen; 3.6

Ulf Riebesell MARUM – Center for Marine Environmental Science; 6.4

Ludwig Ries Federal Environment Agency; 2.9, 2.10, 2.11, 2.13

Stefan Rösner Deutscher Wetterdienst; 1, 7

Friedhelm Rosenke Lower Saxony Ministry of the Interior and Sports; 4.9

Tilo Schöne German Research Centre for Geosciences; 6.3

Dieter Schrader Federal Maritime and Hydrographic Agency; 3.4

Klaus-Jürgen Schreiber Deutscher Wetterdienst; 1, 7

Marc Schröder Deutscher Wetterdienst; 2.4

Detlef Stammer Centre for Marine and Atmospheric Sciences; 3.2, 3.3

Willibald Stichler Institute of Groundwater Ecology, Helmholtz Zentrum München; 4.4

Christine Stumpp Institute of Groundwater Ecology, Helmholtz Zentrum München; 4.4

Frank Toussaint German Climate Computing Centre; 5.4

Hans Josef Theis Federal Institute of Hydrology; 4.3

Astrid Uhlmann Federal Office for Agriculture and Food; 4.9

Holger Vömel Deutscher Wetterdienst; 2.7, 5.8

Martin Wegehenkel Leibniz Centre for Agricultural Landscape Research; 4.10

Sieglinde Weigelt-Krenz Federal Maritime and Hydrographic Agency; 3.8, 3.9

Nicole Wellbrock Institute of Climate-Smart Agriculture; 4.8

Klaus-Peter Wittich Deutscher Wetterdienst; 4.9

Kirsten Zimmermann Deutscher Wetterdienst; 4.11

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121 Abbreviations

AARI Arctic and Antarctic Research Institute BGR Bundesanstalt für Geowissenschaften und Rohstoffe (Federal Institute for Geosciences and Natural Resources) AATSR Advanced Along-Track Scanning Radiometer

BKG Bundesamt für Kartographie und Geodäsie (German ACP Atmospheric Composition Portal Federal Agency for Cartography and Geodesy)

ACTRIS Aerosols, Clouds, and Trace gases Research BLE Bundesanstalt für Landwirtschaft und Ernährung InfraStructure Network (Federal Office for Agriculture and Food)

AGU American Geophysical Union BLMP Bund/Länder-Messprogramm Meeresumwelt (German Marine Monitoring Programme) AirBase European Air quality dataBase BMBF Bundesministerium für Bildung und Forschung ALOHA A Long-term Oligotrophic Habitat Assessment (Federal Ministry of Education and Research)

ALOMAR Arctic Lidar Observatory for BMELV Bundesministerium für Ernährung, Landwirtschaft Middle Atmosphere Research und Verbraucherschutz (Federal Ministry of Food, Agriculture and Consumer Protection)

AMBAV Agrarmeteorologisches Modell zur Berechnung der aktuellen Evapotranspiration BMU Bundesministerium für Umwelt, Naturschutz und (Agrometeorological model for the calculation of Reaktorsicherheit (Federal Ministry for the Environ- current evapotranspiration) ment, Nature Conservation and Nuclear Safety)

AMSeL Mean Sea Level and Tidal Analysis at the German BMVBS Bundesministerium für Verkehr, Bau und North Sea Coastline Stadtentwicklung (Federal Ministry of Transport, Building and Urban Development)

Antarkt- Gesetz zur Ausführung des Umweltschutzprotokolls UmwSchProtAG vom 4. Oktober 1991 zum Antarktis-Vertrag BOOS Baltic Operational Oceanographic System (Act implementing the Protocol of Environmental Protection to the Antarctic Treaty of 4 October 1991) BSH Bundesamt für Seeschifffahrt und Hydrographie (Federal Maritime and Hydrographic Agency) AOPC Atmospheric Observation Panel for Climate BSRN Baseline Surface Radiation Networks Aquarius/SAC-D Fourth satellite of the Argentinian SAC scientific satellite series BW Bundeswehr (Federal Armed Forces)

ARGO Global array of 3,000 free-drifting profiling floats BZE Bodenzustandserhebung (national soil survey) that measures the temperature and salinity of the upper 2,000 m of the ocean BZE-LW Bodenzustandserhebung Landwirtschaft (German agricultural soil inventory) ATSR-2 Along Track Scanning Radiometer

BZE Wald Bodenzustandserhebung im Wald AVHRR Advanced Very High Resolution Radiometer (national forest soil survey)

AWI Alfred Wegener Institute, CARBOCHANGE EU FP7 Project on Changes in carbon uptake and Helmholtz Centre for Polar and Marine Research emissions by oceans in a changing climate

BAdW Bavarian Academy of Sciences and Humanities CarboEurope Integrated Project CarboEurope-IP – Assessment of the European Terrestrial Carbon Balance BATS Bermuda Atlantic Time-series Study CARBOOCEAN Integrated project on marine carbon sources and BBodSchG Bundesbodenschutzgesetz (Federal Soil Protection Act) sinks assessment

BC Black carbon CARIBIC Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container

BDF II Boden-Dauerbeobachtungsfläche II (permanent soil observation plot, type II) CARINA project CARbon dioxide IN the Atlantic Ocean data synthesis

BfG Bundesanstalt für Gewässerkunde (Federal Institute of Hydrology) CAS WMO Commission for Atmospheric Sciences

BGBI Bundesgesetzblatt (Federal Law Gazette) CBS WMO Commission for Basic Systems

122 Annexes Abbreviations 8

CCl WMO Commission for Climatology DCPC Data Collection and Production Centre

CCLM COSMO Climate Limited-area Modelling DDC Data Distribution Centre

CDIAC Carbon Dioxide Information Analysis Center DeStatis Statistisches Bundesamt (Federal Statistical Office)

CDR Climate Data Record DFD Deutsches Fernerkundungsdatenzentrum (German Remote Sensing Data Centre)

CEOS Committee on Earth Observation Satellites DFG Deutsche Forschungsgesellschaft (German Research Foundation) CGMS Coordination Group for Meteorological Satellites

DGFI Deutsches Geodätisches Forschungsinstitut

CH4 Methane (German Geodetic Research Institute)

CHL Chlorophyll DGJ Deutsches Gewässerkundliches Jahrbuch (German Hydrological Yearbook) CHy WMO Commission for Hydrology DIN Dissolved inorganic nitrogen (nitrate, nitrite and ammonium)) CIMO WMO Commission for Instruments and Methods of Observation DKRZ Deutsches Klimarechenzentrum (German Climate Computing Centre) CliC Climate and Cryosphere project

DLR Deutsches Zentrum für Luft- und Raumfahrt CLIMAT A code for reporting monthly climatological data (German Aerospace Center)

CLIVAR WCRP Programme on Climate Variability and DOD Deutsches Ozeanographisches Datenzentrum Predictability (German Oceanographic Data Centre)

Cloudnet Network of stations for the continuous evaluation DOI Digital Object Identifier of cloud and aerosol profiles in operational NWP models

DORIS Doppler Orbitography and Radiopositioning CMIP5 Coupled Model Intercomparison Project Phase 5 Integrated by Satellite

CM SAF EUMETSAT Satellite Application Facility on Climate DU Dobson unit Monitoring DWD Deutscher Wetterdienst CNES Centre National d’Études Spatiales (German Meteorological Service) (French Space Agency) EAN European Aeroallergen Network CNRS Centre national de la recherche scientifique (French National Center for Scientific Research) EarthCARE Earth Clouds, Aerosols and Radiation Explorer

CO Carbon dioxide 2 EBAS Database of atmospheric chemical composition and physical properties Copernicus European Earth observation programme Copernicus, previously known as GMES EC European Community

COSMO-DE COSMO small-scale model for Germany ECMWF European Centre for Medium-Range Weather Forecasts

COSMO-EU COSMO small-scale model for Europe ECOOP European COastal sea OPerational observing and forecasting system COST European Cooperation in Science and Technology ECSN European Climate Support Network CTD Climate Technology and Development Project ECV Essential Climate Variable CVOO Cape Verde Ocean Observatory EEA European Environment Agency CZCS Coastal Zone Color Scanner EEZ Exclusive economic zone D-A-CH Refers to co-operation initiatives between Germany, Austria and Switzerland EFAS European Flood Awareness System

123 EFFIS European Forest Fire Information System GDI Geodateninfrastruktur (Geo Data Infrastructure)

EMEP European Monitoring and Evaluation Programme GDSIDB Global Digital Sea Ice Data Bank

ENSO El Niño Southern Oscillation GEO Group on Earth Observations

ENVISAT ESA Environmental satellite GEOMAR GEOMAR Helmholtz Centre for Ocean Research Kiel

EPN European Phenological Network GEOSS Global Earth Observation System of Systems

EPS Ensemble Prediction System GEWEX Global Energy and Water Exchanges Project

ESA European Space Agency GFMC Global Fire Monitoring Center

ESRL NOAA Earth System Research Laboratory GFZ Helmholtz-Zentrum Potsdam – Deutsches GeoForschungsZentrum GFZ ESTOC European Station for Time series in the Ocean, (Helmholtz Centre Potsdam – German Research Canary Islands Centre for Geosciences)

EU European Union GHRSST Group for High Resolution Sea Surface Temperature EUMETNET Economic Interest Grouping (EIG) of European National Meteorological Services GHz Gigahertz

EUMETSAT European Organisation for the Exploitation of GIA Glacial Isostatic Adjustment Meteorological Satellites

GIS Geographic information system EUREF European Geodetic Reference Frame

GLONASS Globalnaya Navigatsionnaya Sputnikovaya EURO4M EUropean Reanalysis and Observations For Sistema, Russian satellite navigation system Monitoring project

GLOSS Global Sea Level Observing System EuroGOOS European Global Ocean Observing System

GME Global Model Extended (global numerical EuroSITES European Ocean Observatory Network weather forecasting model of the DWD)

Eurostat Statistical office of the European Union GMES Global Monitoring for Environment and Security, now renamed Copernicus EUROWATERNET The European Environment Agency‘s Monitoring and Information Network for Inland GNIP Global Network for Isotopes in Precipitation Water Resources

EUSAAR European Supersites for Atmospheric Aerosol GNSS Global Navigation Satellite System Research GOFC-GOLD Global Observation of Forest and Land Cover Dynamics FAO Food and Agriculture Organization of the United Nations GOME Global Ozone Monitoring Experiment

FINO1 Research platform in the North Sea GOOS Global Ocean Observing System

FMI Finnish Meteorological Institute GOSIC Global Observing Systems Information Center

FP7 Seventh Framework Programme for Research GPCC Global Precipitation Climatology Centre of the European Union

FRD EU Flood Risk Directive GPCP Global Precipitation Climatology Project

FS Lightship, research ship GPS Global positioning system

FTIR Fourier Transform Infrared Spectroscope GRDC Global Runoff Data Center

Galileo European Satellite Navigation System GRUAN GCOS Reference Upper-Air Network

GAW Global Atmosphere Watch GSN GCOS Surface Network

GCM General Circulation Model GSNMC GCOS Surface Network Monitoring Centre

GCOS Global Climate Observing System GTN-H Global Terrestrial Network - Hydrology

124 Annexes Abbreviations 8 GTN-R Global Terrestrial Network for River Discharge IGOE Institut für Grundwasserökologie (Institute of Groundwater Ecology)

GTOS Global Terrestrial Observing System IGRAC International Groundwater Resources Assessment Centre GTS WMO Global Telecommunication System

IGS International GNSS Service GUAN GCOS Upper-Air Network

IHP UNESCO International Hydrological Programme GWB Groundwater body

IICWG International Ice Charting Working Group GWD Groundwater directive

in situ Measurements in specific places HCFC Hydro-chlorofluorocarbon

INSPIRE Infrastructure for Spatial Information HD(CP)2 High definition clouds and precipitation for advancing in the European Community climate prediction INSTAAR Institute of Arctic and Alpine Research HGF Helmholtz-Gemeinschaft Deutscher Forschungszentren (Helmholtz Association of German Research Centers) IOC Intergovernmental Oceanographic Commission of UNESCO HMGU Helmholtz Zentrum München – German Research Center for Environmental Health IOCCP International Ocean Carbon Coordination Project

HOAPS Hamburg Ocean Atmosphere Parameters and Fluxes IODP Integrated Ocean Drilling Program from Satellite Data

IOW Leibniz-Institut für Ostseeforschung Warnemünde HOMPRA GPCC Homogenized Precipitation Analysis (Leibniz Institute for Baltic Sea Research, Warnemünde)

HOT Hawaii Ocean Time-series IP Integrated project hPa Hektopascal IPCC Intergovernmental Panel on Climate Change

HWRP WMO Hydrology and Water Resources Programme IPG International Phenological Gardens

Hz Hertz IPWG International Precipitation Working Group

HZG Helmholtz-Zentrum Geesthacht Zentrum für IUP Institut für Umweltphysik, Universität Bremen Materialforschung und Küstenforschung (Institute of Environmental Physics, Bremen University) (Centre for Materials and Coastal Research)

JCOMM Joint WMO-IOC Technical Commission for IAEA International Atomic Energy Agency Oceanography and Marine Meteorology

IAHS International Association of Hydrological Sciences JMA Japan Meteorological Agency

ICES International Council for the Exploration of the Sea JRC EU Joint Research Centre

ICOADS International Comprehensive Ocean-Atmosphere K Kelvin Data Set

KEG Kommission für Erdmessung und Glaziologie ICOS European research infrastructure (Commission for Geodesy and Glaciology) “Integrated Carbon Observation System” KFKI Kuratorium für Forschung im Küsteningenieurwesen ICP Forests International Co-operative Programme on Assessment (German Coastal Engineering Research Council) and Monitoring of Air Pollution Effects on Forests KLIDADIGI KLImaDAten DIGItalisierung ICSU International Council for Science (DWD project on the digitisation of climate data)

IFM Hamburg Institut für Meereskunde, Universität Hamburg KMI Koninklijk Meteorologisch Instituut (Institute of Oceanography, University of Hamburg) (Royal Meteorological Institute of Belgium)

IfT Leibniz-Institut für Troposphärenforschung e.V. (TROPOS) LANUV Landesamt für Natur, Umwelt und Verbraucherschutz (Leibniz Institute for Tropospheric Research (TROPOS)) Nordrhein-Westfalen (North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection) IGACO Integrated Global Atmospheric Chemistry Observations

LfU Bayerisches Landesamt für Umwelt IGY International Geophysical Year (Bavarian Environment Agency)

125 LIDAR Light Detection And Ranging NDMC Network for the Detection of Mesopause Change

LKN-SH Landesbetrieb für Küstenschutz, Nationalpark und NILU Norwegian Institute for Air Research Meeresschutz Schleswig-Holstein (Schleswig-Holstein’s Government-Owned Company for Coastal Protection, National Parks and NIR National Inventory Report Ocean Protection) NMHS National Meteorological and Hydrological Service LLCF Long-lived climate forcers NOAA National Oceanic and Atmospheric Administration LMT Local mean time NOOS North West European Shelf Operational Oceanographic LMU Munich Ludwig-Maximilians-Universität München System (Ludwig Maximilian University of Munich) NSB-2 North sea buoy 2 LSA SAF EUMETSAT Land Surface Analysis Satellite Application Facility NSIDC National Snow and Ice Data Center

LSW Labrador Sea Water OceanSITES Worldwide system of long-term, deepwater reference stations LUCAS Land use/cover area frame survey OECD Organisation for Economic Co-operation and MARNET Marines Umweltmessnetz in Nord- und Ostsee Development (Marine Environmental Monitoring Network in the North Sea and Baltic Sea) OSI SAF EUMETSAT Satellite Application Facility on Ocean and Sea Ice MARUM Zentrum für Marine Umweltwissenschaften (Center for Marine Environmental Science) OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic MCAP Monte-Carlo autoregressive padding (Oslo-Paris Convention)

MD Meteorological Service of the former GDR PANGAEA® Data Publisher for Earth & Environmental Science

MERIS Programmable, medium-spectral resolution, pCO2 CO2 partial pressure imaging spectrometer operating in the solar reflective spectral range PDO Pacific Decadal Oscillation

MOC Meridional overturning circulation PEP Pan European Phenology database

MODIS Aqua EOS PM satellite with moderate-resolution imaging spectroradiometer PEP725 Pan European Phenology project 725

MODIS Terra EOS AM satellite with moderate-resolution PermaNET Permafrost Monitoring Network imaging spectroradiometer PID German Pollen Information Service Foundation MOL-RAO Lindenberg Meteorological Observatory - Richard Assmann Observatory PM10 Fine particulate matter

MPI Max Planck Institute PNA Pacific/North American circulation pattern

MPI-ESM LR MPI Earth System Model with Low Resolution PSMSL Permanent Service for Mean Sea Level

MSE Mean squared error RADOLAN Radar online calibration method

MSFD Marine Strategy Framework Directive RBCN Regional Basic Climatological Network

MUDAB Marine Environmental Data Base RCC-CM WMO Regional Climate Centre Network (RA VI) Offenbach Node on Climate Monitoring MyOcean Ocean Monitoring and Forecasting service project under Copernicus (former GMES) RCP Representative Concentration Pathways

N O Nitrous oxice, laughing gas 2 REMO Regional model REMO

NAO North Atlantic Oscillation RMSL Relative mean sea level

NASA National Aeronautics and Space Administration ROSE/DLR Global 3D-chemistry-transport model used to derive vertically resolved ozone distributions NDACC Network for the Detection of from ERS2-GOME total column ozone and ENVISAT Atmospheric Composition Change ozone profile measurements

126 Annexes Abbreviations 8 SAF EUMETSAT Satellite Application Facility WasEG Wasserentnahmeentgeltgesetz (Water usage payment act) SAR Search and Rescue WaStrG Bundeswasserstraßengesetz (Federal Waterways Act) SeaWiFS NOAA Sea-viewing Wide Field-of-view Sensor project WCC World Climate Conference SeeAufgG Gesetz über die Aufgaben des Bundes auf dem Gebiet der Seeschifffahrt WCP World Climate Programme (Maritime Shipping (Federal Competences) Act)

WCRP World Climate Research Programme

SF6 Sulfur hexaflouride WDC-Climate World Data Center for Climate SFB DFG Collaborative Research Centre

WDCGG GAW World Data Centre for Greenhouse Gases SI International standard units

WDC-Mare World Data Center for Marine Environmental Sciences SLR Satellite Laser Ranging

WDC-RSAT World Data Center for Remote Sensing of the SMHI Swedish Meteorological and Hydrological Institute Atmosphere

SMOS ESA Soil Moisture and Ocean Salinity satellite WDS ICSU World Data System

SOCAT Surface Ocean CO2 Atlas WFD EU Water Framework Directive

SSA Singular System Analysis WGMS World Glacier Monitoring Service

SSM/I Special Sensor Microwave Imager WHG Wasserhaushaltsgesetz (Federal Water Act)

TCCON Total Carbon Column Observing Network WHYMAP World-wide Hydrogeological Mapping and Assessment Programme TDR Time domain reflectometry WISER Water Isotope System for Data Analysis, Visualization and Electronic Retrieval TENATSO Tropical Eastern North Atlantic Time Series Observatory

WMO World Meteorological Organization TIGA Tide Gauge Benchmark Monitoring project

WMO RA VI WMO Regional Association VI UBA Umweltbundesamt (Federal Environment Agency) (Europe and Middle East)

UFS Umweltforschungsstation WMO TD WMO Technical Document (environmental research station)

WOCE World Ocean Circulation Experiment UFS Unbemanntes Feuerschifff (unmanned lightship)

WRDC World Radiation Data Centre UFS TW Ems Unmanned deep water way lightship Ems

WRMC World Radiation Monitoring Center UIG Umweltinformationsgesetz (Federal Environmental Information Act) WSA Wasser- und Schifffahrtsamt (Waterways and Shipping Office) UNECE United Nations Economic Commission for Europe

WSV Wasser- und Schifffahrtsverwaltung UNEP United Nations Environment Programme (German Federal Waterways and Shipping Administration) UNESCO United Nations Educational, Scientific and Cultural Organization ZALF Leibniz-Zentrum für Agrarlandschaftsforschung (Leibniz Centre for Agricultural Landscape Research) UNFCCC United Nations Framework Convention on Climate Change ZAMF Zentrum für Agrarmeteorologische Forschung Braunschweig UNISDR United Nations Office for Disaster Risk Reduction (Braunschweig Agrometeorological Research Centre of DWD)

VASClimO DWD Variability Analysis of Surface Climate Observations project ZAMG Zentralanstalt für Meteorologie und Geodynamik (Central Institute for Meteorology and Geodynamics, Austria) VF Vernagtferner glacier

ZMMF Zentrum für Medizin-Meteorologische Forschung VOS Voluntary Observing Ships (DWD Centre for Human Biometeorological Research)

127 Picture credits

Front cover DWD Pages 56/57 Holger Klein/BSH

Page 3 BMVBS Pages 58/59 Holger Klein/BSH

Pages 4/5 Claudia Hinz/DWD Pages 60/61 Thomas Kreuz/BSH

Page 6 Frederike Egerer; Pages 62/63 BfG Iakov Filimonov/panthermedia.net; Igor Stepovik/Fotolia.com Pages 64/65 suze/photocase.com

Page 7 Viktoriya Sukhanova/Fotolia.com; Pages 66/67 daniel.schoenen/photocase.com Jürgen Janneck/AWI; Claudia Hinz/DWD Pages 68/69 Jumo/Fotolia.com

Pages 8/9 mirpic/Fotolia.com Pages 70/71 pollux/Fotolia.com

Pages 12/13 Bernd Loose/AWI Pages 72/73 Dr. Hagg/LMU Munich

Pages 14/15 Constantin Eichel; Corney/fc-foto.de Pages 74/75 Jörg Rapp/DWD

Pages 16/17 filius/Fotolia.com Pages 76/77 Christian Stoll/Fotolia.com

Pages 18/19 Galyna Andrushko/Fotolia.com Pages 78/79 MI Brandenburg

Pages 20/21 Creative Collection (ccvision.de) Pages 80/81 Igor Stepovik/Fotolia.com

Pages 24/25 MOL/DWD Pages 82/83 Undine Aust/Fotolia.com

Pages 26/27 Anton Petrus/Fotolia.com Pages 84/85 Pauline Borgmann

Pages 28/29 Roman Sakhno/Fotolia.com Pages 86/87 Thorsten Schier/Fotolia.com

Pages 30/31 Frederike Egerer Pages 88/89 WRMC

Pages 32/33 Andreas Fitz/123rf.com Pages 90/91 DKRZ

Pages 34/35 Dudarev Mikhail/Fotolia.com Pages 92/93 EUMETSAT

Pages 36/37 Fel1ks/Fotolia.com Pages 94/95 NASA, GFMC

Pages 38/39 Creative Collection (ccvision.de) Pages 96/97 Viktoriya Sukhanova/Fotolia.com

Pages 40/41 Martin Murnsky/panthermedia.net Pages 98/99 Holger Vömel, Franz Immler/DWD

Pages 42/43 Jörg Rapp/DWD Pages 100/101 EUMETSAT

Pages 44/45 Iakov Filimonov/panthermedia.net Pages 102/103 Jürgen Janneck/AWI

Pages 46/47 Paul Stock/Fotolia.com Pages 104/105 KEG

Pages 48/49 Birgit Klein/BSH Pages 106/107 DeVIce/Fotolia.com

Pages 50/51 BSH Pages 108/109 Björn Fiedler/GEOMAR

Pages 52/53 Frank Sakuth/BSH Pages 110/111 vmakt/Fotolia.com

Pages 54/55 Institute of Environmental Physics/University of Bremen Pages 112/113 Claudia Hinz/DWD

128 Annexes Picture credits 8