Climate Change in Latvia CLIMATE CHANGE IN LATVIA Editor Māris Kļaviņš UDK 551(474.3) Cl 620 The publication of the book has been supported by the INTERREG III B project ASTRA, Latvian National Research Programme: “Climate Change and Waters”, and Latvian Science Council cooperation project “Effects of Climate Change on the Nature of Latvia, 2006-2009” Co-editors: M. sc. Valērijs Rodinovs Dr. biol. Guntis Brūmelis Dr. geol. Ervīns Lukševičs Dr. biol. Viesturs Melecis Dr. chem. Linda Eglīte Dr. geogr. Agrita Briede Dr. geogr. Elga Apsīte Editor-in-chief: Professor Māris Kļaviņš English language editor: Māra Antenišķe Cover photo: Ivars Druvietis Lay-out and Cover design: Arnis Čakstiņš The authors acknowledge Latvian Environment, Geology and Meteorology Agency for providing hydrological and meteorological data for climate change analysis All the papers published in the present volume have been reviewed. No part of the volume may be reproduced in any form without the written permission of the publisher. ISBN 9984-802-70-1 © Latvijas Universitāte, 2007 5 CONTENTS Foreword ............................................................................................................................. 7 THE CHARACTER OF CLIMATE CHANGE ................................................................ 9 Lita Lizuma, Māris Kļaviņš, Agrita Briede, Valērijs Rodinovs Long-term Changes of Air Temperature in Latvia ............................................................. 11 Māris Kļaviņš, Valērijs Rodinovs Long-term Changes of River Discharge Regime in Latvia ................................................ 21 Agrita Briede, Lita Lizuma Long-term Variability of Precipitation in the Territory of Latvia ...................................... 35 Māris Kļaviņš, Valērijs Rodinovs, Anita Draveniece Large-scale Atmospheric Circulation Processes as the Driving Force in the Climatic Turning Points and Regime Shifts in the Baltic Region ........................... 45 Māris Kļaviņš, Agrita Briede, Valērijs Rodinovs Ice Regime of Rivers in Latvia in Relation to Climatic Variability and North Atlantic Oscillation ............................................................................................ 58 Anita Draveniece, Agrita Briede, Valērijs Rodinovs, Māris Kļaviņš Long-term Changes of Snow Cover in Latvia as an Indicator of Climate Variability ....... 73 Tatjana Koļcova, Lita Lizuma, Svetlana Rogozova, Marta Smith Climate Change Impacts on Hydrological Processes in Latvia ......................................... 86 Uldis Bethers, Juris Seņņikovs Mathematical Modelling of the Hydrological Processes in the Aiviekste River Basin ..... 96 THE IMPACTS OF CLIMATE CHANGE ....................................................................... 121 Gunta Spriņģe, Māris Kļaviņs, Jānis Birzaks, Agrita Briede, Ivars Druvietis, Linda Eglīte, Laura Grīnberga, Agnija Skuja Climate Change and Its Impacts in Inland Surface Waters ................................................ 123 Gunta Grišule, Agrita Briede Phenological Time Series in Latvia as Climate Change Indicators ................................... 144 Māris Laiviņš, Solvita Rūsiņa The Dynamics of Pine Forest Vegetation as an Indicator of Climate Change and Eutrophication in the Integrated Monitoring Stations in Latvia ................................. 154 Ivars Druvietis, Agrita Briede, Laura Grīnberga, Elga Parele, Valērijs Rodinovs, Gunta Spriņģe Long-term Assessment of Hydroecosystem of the River Salaca, North Vidzeme Biosphere Reserve, Latvia ........................................................................ 173 Didzis Elferts The Influence of Climatic Factors on the Radial Growth of the Scots Pine on a Dune Island of Raganas Mire ......................................................... 187 Gunta Spriņģe, Agrita Briede, Ivars Druvietis, Elga Parele, Valērijs Rodinovs Changes of the Hydroecosystem of Lagoon Lake Engure, Latvia (1995-2006) ............... 194 Māris Baltiņš, Māris Kļaviņš, Valērijs Rodinovs Climate Related Mortality Changes in Latvia, 2000-2004 ................................................ 210 6 Climate Change in Latvia CLIMATE POLICY AND TECHNOLOGIES ................................................................... 217 Ieva Bruņeniece, Valdis Bisters, Māris Kļaviņš Climate Change Policy Instruments in Latvia .................................................................... 219 Dagnija Blumberga, Marika Rochas, Anna Vološčuka, Ivars Veidenbergs Benchmarking for Energy Climate Technologies in Latvia ............................................... 252 Sylvestre Njakou Djomo, Dagnija Blumberga Combining the “Well to Gate” and Scenarios Analyses to Assess Hydrogen Transition Pathway in Latvia ............................................................................................................... 261 7 FOREWORD Climate change is one of the most topical issues in the present society, considering its relevance for each and every human being in the world. However, many of the discussed questions are still the subject of academic studies. Climate change is undoubtedly global, nevertheless, its local manifestation very much depends on regional processes and features. Thus, taking into account the diversity of local (regional) processes, regional studies of climate change impacts are highly relevant. The aim of this book is to analyse climate change patterns and their possible influences on environmental processes and nature of Latvia thus filling in the gaps of knowledge about the character of climate change. Editor Māris Kļaviņš The Character of Climate Change Climate Change in Latvia 10 Climate Change in Latvia The Character of Climate Change 11 Long-term Changes of Air Temperature in Latvia Lita Lizuma*, Māris Kļaviņš, Agrita Briede, Valērijs Rodinovs University of Latvia, Faculty of Geographical and Earth Sciences, Raiņa blvd. 19, LV 1586, Rīga, Latvia *Latvian Environment, Geology and Meteorology Agency, Maskavas str. 165, LV 1019, Rīga, Latvia Long-term changes of air temperature can be considered one of the most important indicators of climate change. The long term changes of air temperature in Latvia were investigated. A significant increase in air temperature can be observed for the whole period of observations, however, it has been more expressed during the last decades. The most significant increase of air temperature can be observed in cities, especially, Rīga. Air temperatures have increased, 24-hour amplitudes in air temperature have decreased. The character of changes stresses the importance of local changes in urban environment. Key words: long-term variability, temperature, trends, Latvia INTRODUCTION Climate change and global warming are among the most important environmental problems today. Continuously increasing levels of atmospheric carbon dioxide have been recorded for over five decades, resulting in global warming. This phenomenon has been reported to have increased the global average surface temperature by 0.6±0.2 ◦C (IPCC 2001), whose increase may be responsible for climate change (including, for example, the changes in the amount of precipitation and storm patterns). Qualitative evaluation of these changes is based on an analysis of long-term meteorological data series. There are numerous studies in which the general trends of air temperature changes in northern Europe have been demonstrated (Jaagus 1996; Jaagus 1998; Keevallik 2003; Jaagus 2006). Similar studies have also demonstrated changes in Latvia’s climate over the last century (Treilība 1995; Lizuma 2000, 1999). The aim of this study is 12 Climate Change in Latvia to analyze the most important changes in the air temperature in Latvia since the start of the regular observations, especially considering the availability of unique data series of meteorological data collected at the country’s oldest meteorological station, known as Rīga-University. The station was established in 1795 and, along with similar facilities in Vilnius and Tallinn, is among the oldest in the Baltic region. Inasmuch as the Rīga-University meteorological station is located in the very center of the city, its data can be used to study the conditions of an urban environment and changes therein. MATERIALS AND METHODS Data used in the study were obtained from the Latvian Environment, Geology and Meteorology Agency, from 22 stations. To characterize the climate and its changes, data on temperature were used. To investigate the links to wide-scale climatic forcing, we used the extended North Atlantic oscillation (NAO) index (Luterbacker et al. 2002). The sum of normalized deviations from the reference climate indicator values has been expressed as Σ(K-1). The multivariate Mann-Kendall test (as described by Hirsch et al. 1982; Hirsch and Slack 1984) for monotone trends in time series of data grouped by sites was chosen for the determination of trends, as it is a relatively robust method concerning missing data, and it lacks strict requirements regarding data heteroscedasticity. The Mann-Kendall test was applied separately to each variable at each site, at a significance level of p<0.5. The trend was considered as statistically significant at a 5 % level if the test statistic was greater than 2 or less than -2 (Hirsch and Slack 1984). RESULTS AND DISCUSSION Climatic conditions and air temperature in Latvia are influenced by large scale atmospheric circulation processes, intensity of Solar irradiation, and also by local factors such as vicinity to the Baltic Sea. Mean annual air temperature in Latvia (Fig. 1) (from 22 meteorological