IAEA-TECDOC-1453 Isotopic composition of precipitation in the Mediterranean Basin in relation to air circulation patterns and climate Final report of a coordinated research project 2000–2004 October 2005 IAEA-TECDOC-1453 Isotopic composition of precipitation in the Mediterranean Basin in relation to air circulation patterns and climate Final report of a coordinated research project 2000–2004 October 2005 The originating Section of this publication in the IAEA was: Isotope Hydrology Section International Atomic Energy Agency Wagramer Strasse 5 P.O. Box 100 A-1400 Vienna, Austria ISOTOPIC COMPOSITION OF PRECIPITATION IN THE MEDITERRANEAN BASIN IN RELATION TO AIR CIRCULATION PATTERNS AND CLIMATE IAEA, VIENNA, 2005 IAEA-TECDOC-1453 ISBN 92–0–105305–3 ISSN 1011–4289 © IAEA, 2005 Printed by the IAEA in Austria October 2005 FOREWORD The IAEA has operated the Global Network of Isotopes in Precipitation (GNIP) since 1961. There has been an increased need for GNIP data following the recognition of the role of precipitation stable isotopes in better simulating the hydrologic cycle in climate models. The isotopic composition of precipitation is closely related to rain formation conditions, i.e. with the temperature of formation, the origin of air masses, and the degree and mechanism of rainout. Over the last twenty years, use of GNIP data in climate model has indicated a need for a much more refined, process-based understanding of isotope variations in the hydrological cycle. This coordinated research project (CRP) was initiated with the aim of collecting new data on higher spatial density and temporal frequency to improve our knowledge of environmental isotope variations in atmospheric waters. The Mediterranean region was chosen for this study so that climatic and meteorological conditions, which govern the rain formation process, and their variations along east-west and north-south directions, could be investigated. In addition, the first steps of the hydrological cycle, that is evaporation from seawater and condensation of atmospheric vapour could also be studied. The IAEA invited scientists from institutes in Mediterranean countries who have already been involved in studies related to the isotopic composition of precipitation to take part in this CRP, which was initiated in 2000. This publication is a summary of the results achieved in the CRP. The overall achievements are presented as the executive summary, and the detailed findings are presented in each contribution. These results were presented in the final research coordination meeting, held in Vienna from 15 to 19 March 2004. The results of this CRP are relevant to the Member State scientists conducting hydrological research. In addition, the results would contribute to the IAEA programme on water resources, in particular to its activities related to water resources assessment in Middle East and North African countries, to marine environment studies in the Mediterranean Sea, the Black Sea, the Caspian Sea, and the Red Sea and to the Global Network of Isotopes in Precipitation programme. The IAEA officer responsible for this publication was L. Gourcy of the Division of Physical and Chemical Sciences. EDITORIAL NOTE This publication has been prepared from the original material as submitted by the authors. The views expressed do not necessarily reflect those of the IAEA, the governments of the nominating Member States or the nominating organizations. The use of particular designations of countries or territories does not imply any judgement by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions or of the delimitation of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the part of the IAEA. The authors are responsible for having obtained the necessary permission for the IAEA to reproduce, translate or use material from sources already protected by copyrights. CONTENTS Summary .................................................................................................................................... 1 Isotopic composition of precipitation from Algiers and Assekrem ........................................... 5 O. Saighi Isotopic composition of precipitation in Austria in relation to air circulation patterns and climate............................................................................................................. 19 D. Rank, W. Papesch Tritium and stable isotope distribution in the atmosphere at the coastal region of Croatia.................................................................................................................. 37 N. Horvatinčić, I. Krajcar Bronić, J. Barešić, B. Obelić, S. Vidič Effect of synoptic and climatic situations on fractionation of stable isotopes in rainwater over Egypt and east Mediterranean................................................................. 51 A.M. El-Asrag Oxygen-18 and deuterium contents over Mount Lebanon related to air mass trajectories and local parameters ......................................................................................... 75 A. Aouad-Rizk, J.L. Job, W. Najem, Y. Travi, B. Blavoux, L.Gourcy Stable isotopes in rainfall over Greece: Results of the 2000–2003 measurement campaign ....................................................................................................... 83 A.A. Argiriou, S.P. Lykoutis The isotope composition of atmospheric waters in Israel’s coastal plains .............................. 99 J.R. Gat, R. Ben-Mair, R. Yam, D. Yakir, H. Wernli Stable isotopes (δ18O, δ2H) and tritium in precipitation: Results and comparison with groundwater perched aquifers in Central Italy ...................................... 115 P. Bono, R. Gonfiantini, M. Alessio, C. Fiori, L. D'Amelio Isotopic composition of precipitation at three Moroccan stations influenced by Oceanic and Mediterranean air masses ........................................................................ 125 B. Ouda, A. El Hamdaoui, M. Ibn Majah Isotopic composition of rain and water vapour samples from Lisbon region: Characterization of monthly and daily events…………………………… ..................................................................... 141 P.M.M. Carreira, M.F. Araujo, D. Nunes Isotopic composition of precipitation in Slovenia ................................................................ 157 P. Vreča, T. Kanduč, S. Žigon, Z. Trkov Isotope composition of precipitation and water vapour in the Iberian Peninsula ......................................................................................................... 173 L.J. Araguas-Araguas, M.F. Diaz Teijeiro The temporal and seasonal variation of H-2 and O-18 in atmospheric water vapour and precipitation from Ankara, Turkey in relation to air mass trajectories at Mediterranean Basin ................................................................................... 191 A. Dirican, S. Ünal, Y. Acar, M. Demircan Annex 1: Sampling network................................................................................................... 215 Annex 2: Atmospheric water vapour sampling device............................................................ 217 Annex 3: Monthly and daily precipitation and water vapour data obtained from 2001 to 2004 around the Mediterranean basin.......................................................... 219 List of participants ................................................................................................................. 221 SUMMARY 1. INTRODUCTION The objectives of this Coordinated Research Programme (CRP) were the assessment of the variation of the isotopic values along the main directions west-east and south-north of the Mediterranean basin; the correlation between these variations and the main climatic and meteorological parameters; the determination of physical phenomena in compliant place and the refinement of a process-based understanding to fully realize the value of isotopic data in hydrological and climate studies. The 18O/2H analyses of daily precipitation sampling and water vapour give valuable information for climate studies. The conclusions drawn from the regional scale interpretation of data obtained by the scientists is summarized here. The fourteen Mediterranean countries participating in this research programme carried out the monthly sampling of precipitation at 84 stations from January 2001 to December 2003. Daily or event-based precipitation sampling was also performed at 32 stations (Annex 1). Water vapour sampling was done at eight stations. This sampling was continuously performed during 48 hours starting Monday morning and Wednesday afternoon. The sampling of atmospheric water vapour was performed using similar equipment developed at the IAEA Isotope Hydrology laboratory. Liquid nitrogen cold traps were used when sampling (Annex 2). Stable isotopes analyses (18O and 2H) were carried out for all samples. Tritium analyses were only performed at selected stations on a monthly basis. In order to reduce the number of isotopes analyses to be done, two sampling periods were chosen for daily/event based and water vapour sampling; October 2001 to March 2002 and October 2002 to March 2003. The minimum information collected at each station is the basic meteorological data (surface air temperature and rain amount). Synoptic weather maps,