The Climate of Israel Observation, Research and Applications

THE CLIMATE OF ISRAEL OBSERVATION, RESEARCH AND APPLICATIONS

First published in Hebrew by Bar-Han University Press

Yair Goldreich THE CLIMATE OF ISRAEL Observations, Research and Application

j"""~U "'N' 'N'~'!1 t3"PNf1 tn'lJ'" "j:m ,n"£J~n THE CLIMATE OF ISRAEL OBSERVATION, RESEARCH AND APPLICATION

Yair Goldreich Bar-Ilan University Ramat-Gan. Israel

Springer Science+Business Media, LLC ISBN 978-1-4613-5200-6 ISBN 978-1-4615-0697-3 (eBook) DOI 10.1007/978-1-4615-0697-3

1098765432 A C.I.P. record for this book is available from the Library of Congress

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No par! of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Preface

This book describes and analyses various aspects of Israeli climate. This work also elucidates how both man and nature adjust to various climates. The first part (Chapters 1-9) deals with the meteorological and climatological network stations, the history of climate research in Israel, analysis of the local climate by season, and a discussion of the climate variables their spatial and temporal distribution. The second part (Chapters 10-14) of this work is devoted to a survey of applied climatology. This part presents information on weather forecasting, rainfall enhancement, air quality monitoring, and various climatological aspects of planning. There is no sharp division between theoretical and applied climatology topics. Moreover, though various sections seem exclusively theoretical, they also include important applications for various real life situations (such as rainfall intensities (Section 5.3), frost, frost damage (Section 6.2.4), degree-days (Section 6.2.5) and heat stress (Section 6.2.6). Professionals and university students of geography and earth science, meteorology and climatology, even high school students majoring in geography will be able to use this book as a basic reference work. Researchers in atmospheric science can also use this work as an important source of reference. Students of agriculture will also gain theoretical and practical insights. Even architects and engineers will gain another perspective in their fields.

A comprehensive glossary was included to help readers to better understand the more technical and specialized terms used in the text. To facilitate fluent reading, lengthy and detailed explanations were excluded. Efforts were made to keep footnotes few and concise.

For the readers' convenience, the full bibliography instead of partial bibliographies (Hebrew and other sources) at the end of each chapter, is presented at the end of the book. References, including the original language of publication, appear within the text (author/s, year of publication). References not specifically referring to the Mediterranean area are marked with an asterisk (*). When the referred research appears in multiple forms (a Ph.D. dissertation, research report, a scientific journal article; either in Hebrew and another language), only one source is cited. When citing source from various sources, first preference was given to articles published in international journals. Articles appearing in refereed Israeli journals (such as the Israel Journal of Earth Sciences; Israel Meteorological Research Papers), took preference over articles appearing in other local journals. Last preference was given to less accessible sources or unpublished material. Often, particularly with important topics, we have chosen to refer to the less accessible [English] source material as well as the more acceptable Hebrew source material. A last passing comment, the Hebrew language journal, Meteorologia BeIsrael often cited and quoted, has over the thirty years of its publication, changed its format twice. In some volumes each bulletin is paginated separately, while in others there is continuous pagination for the whole volume. Thus, the pagination of this major source varies.

v vi PREFACE

Hebrew terms used in this work are those published in the Meteorological Dictionaryl of the Hebrew Language Academy. Popular Hebrew weather terms were generally avoided. However, to avoid ambiguity popular terms were used. For example, the popular nonscientific term sea breeze was used instead of the scientific term sea wind; because sea wind might here be misinterpreted as a general term referring to a westerly wind.

The new international units (SI - System International), such as meter, kilogram and second were used. For example, the pressure unit Hecto-pascal (hPa) is used, instead of the millibar (which is the same size as the hPa) still commonly used on synoptic charts; work (and energy) units joule were used instead of Langley unit (in the solar radiation domain); when not otherwise mentioned, temperatures are in Celsius. Wind speed units were applied, according to the conventional use in each particular field, meters/seconds, knots, and kmlhour. Hours cited are local wintertime, which is two hours earlier than the UTC (Universal Time Coordinated, formerly Greenwich Mean Time). To change the data from wintertime to summertime (which is three hours earlier than the UTC), an hour should be added to wintertime. Generally, the conventional 5% (0.05) statistical level of significance was applied, this means that there are about 5 chances in 100 that to reject the hypothesis when it should be accepted.

Although it is unconventional to present data in both tables and figures, we have sometimes presented data in both forms. For instance, it is more convenient to examine the spatial distribution on a map and to find the exact value on a table. Geographical data are generally presented by the three longitude strips oflsrael (Coastal Plain, the mountainlhilly region and the Jordan Rift Valley); the data for each strip are displayed from north to south. This is also the conventional display format of Israeli Meteorological Service publications. Only recently, has the Meteorological Service applied a new method to display data, by geo-climate regions (See Fig. 2.10). Using this new system, it is easier to compare data of the same region, yet, using the former system of longitude strips, it is less difficult to locate the specific weather station.

Finally, I would like to thank my colleagues at the various institutions for their assistance in completing this work. A special thanks to those colleagues who critically read and made constructive suggestions for the improvement of the section of the manuscript in their specific field:

Zvi Alperson, Director ofIMS (Chapter 10); Prof. Pinhas Alpert, the Department of Geophysics and Planetary Sciences, Tel-Aviv University (Chapters 3, 4 and Section 11.2); Prof. Stephen Brenner, Israel Oceanographic and Lirnnological Research Ltd. (Section 11.2); Prof. Uri Dayan, Department of Geography, The Hebrew University (Section 12.2); Dr. Eli'ezer Ganor, Head of Physics Unit, Environmental Studies Institute, Ministry of Environment, Ramat Aviv (Chapter 8); Prof. Yoel Gat, Isotopes Department, Weizmann Institute (Section 9.1); Zipora Gat, Head of Agrometeorological Unit, IMS (Chapter 7 and Sections 6.2.4, 13.1); Dr. Michael Graber, (Former) Head of Air Quality Unit, Ministry of Environment (Section 12.2); Prof. Gedalyahu Gvirtzman,

I The Hebrew Language Academy, the Meteorological Service and Massada Publication, 1971. Y.L. Tokatley wrote and published by the Defense Ministry, 1994, an updated dictionary with the same name, including not only the translation ofthe term but also its definition. PREFACE vii

Department of Geography, Bar-Dan University (Section 9.1); Dr. Amiran Ianetz, Research and Development Unit, IMS (Section 6.1); Prof. Haim Kutiel, Department of Geography, Haifa University, (Chapter 5); Eng. Nurit Perlow, Wind Energy Unit Coordinator, Ministry of Energy and Infrastructure (Chapter 14); Prof. Daniel Rosenfeld, Atmospheric Sciences Department the Hebrew University (Chapter 11 and Sections 3.6, 9.3); Sarah Rubin, Head of Climate Unit, IMS (Chapter 2 and Section 6.2); Prof. David Sharon Earth Sciences Institute, The Hebrew University (Section 5.4); Prof. Dov Skibin, the Nuclear Research Center, Negev (Chapter 14 and Section 13.3); Prof. Gerald Stanhill, Water and Soil Institute, Agricultural Research Organization (the Volcani Center), Bet Dagan (Sections 6.1, 7.1); Dr. Lutz Striem formerly of the Nuclear Research Center, Soreq (Chapter 5 and Section 9.2); Yehuda Tokatly, former Director IMS (Chapter I); Samuel Yaffe, former Director IMS (Chapter 4 and Sections 2.4, 5.2.3.4); Prof. Abraham Zangvil, Institute for Desert Research, Ben-Gurion University (Chapters 3, 4).

I would like to thank various publishers, authors, and copyright holders of various publications for the use of figures, tables, maps and photographs: My gratitude is given to Zvi Alperson, Director ofIMS and Samuel Yaffe, former Director, for permission to copy figures and tables from IMS publications and from the Israel Meteorological Research Papers; Ja'akov Lomas, Chairman of the Israeli Meteorological Union, for permission to use material from Meteorologia beIsrael; Weizmann Institute Publication, for material from the Journals: Mada (Fig. 8.8) and Israel Journal of Earth Sciences (Figs. 4.1; 4.3; 4.4; 7.11; 12.3). The publishers of HaSsadeh and Horizons in Geography journals; American Meteorological Society for permission to use material from the journals: Journal of (Climate and) Applied Meteorology (Figs. 4.12; 4.13; 4.14; 4.15; 9.9; 10.2; 10.3; 10.4; 11.4) and Bulletin of the American Meteorological Society (Figs. 3.6; 3.7); American Geophysical Union for permission to use material from the journals: Journal of Geophysical Research (Fig. 9.10) Water Resources Research (Fig. 11.7); Akademische Veriagsgesellschaft the publisher of Geojournal; Elsevier Sequoia A.S. the publisher of Energy and Buildings (Fig. 13.3); Elsevier Nederland the publisher of The Science of the Total Environment (Fig. 12.8); The Royal Meteorological Society the copyrights owner of (International) Journal of Climatology (Fig. 2.6); Pergamon Press Ltd the publisher of Atmospheric Environment and Solar Energy (Figs. 6.1; 6.2; 6.4); Springer Verlag the publisher of the journals: Archiv for Meteorologie Geophysik und Bioklimatologie (Figs. 5.4; 5.8; 9.8) and International Journal ofBiometeorology (Figs. 6.17; 13.1); Chicago University Press the publisher of Journal of Near Eastern Studies; Ohio State University Press the publishers of Geographical Analysis; Inter-Research Science Publication the publisher of Climatic Research (Figs. 6.13; 6.14); Kluwer Academic Publishers group the publisher of the Journals: Climatic Change (Figs. 9.5; 9.6; 9.7) and Boundary Layer Meteorology (Fig. 12.4); John Wiley & Sons the copyrights owner of the book Environmental Geoscience (Figs. 2.3; 2.4); Harvard University Press the copyrights owner of the book The Negev - the Challenge ofa Desert; Balaban ISS the publisher of Developments in Arid Zone Ecology and Environmental Duality; University of Wisconsin the publisher of the book The Earth's Problem Climates (Fig. 3.2; 3.3); Blackwell Scientific Publishers viii PREFACE the owner of the journal Bulletin of the I.A.S.H (Fig. 5.11); The Geography Department of Ben-Gurion University, the publisher of Geographical Research Forum and the publications Climatic Model ofAtmospheric Flow in Be 'er Sheva and Vicinity and Industrial Optimal Siting with Minimal Air Pollution in Ashdod and Vicinity; Butterworth & Co. publisher of Applied Geography (Fig. 14.5); Harrassowitz Verlag the publisher of Zeitsch. d. Deutsch. Palast. - Vereins (Fig. 1.1). The Israel Mapping Center, Ministry of Housing, for figures taken from the Atlas of Israel of both editions; Ministry of Sciences, the publishers of Bulletin of the Research Council of Israel; Agricultural Engineering Faculty, the Technion; T AHAL Consulting. Engineers; The Israeli Medicine Union the publisher of HaRefuah; The Israeli Exploration Society the publisher of Eretz-Israel, Archaeological, Historical and Geographical Studies (D. Amiran Vol.); the publisher of Agriculture Encyclopedia; the editorial board of 'Eretz " research and pUblications in geography; Qiryat-Sefer publisher of Collection of Studies on the Land of Israel by N. Shalem.

The following persons gave permission for use of material: Shula Elbashan for material of the late Daniel Elbashan; Ilia Ashbel for material of the late Prof. Dov Ashbel; the authors Ora Kami; Prof. Haim Kutiel; Dr. Oded Potchter; Architect Arieh Raharnimoff; Dr. Baruch Ronberg; Dr. Milo Rosenberg; Prof. Daniel Rosenfeld; Dr. Hadas Sa'aroni; Shraga Stiefel; Dr. Baruch Ziv.

I have tried my best to locate all the copywrite holders who have rights to cited material, but unfortunately, I was not always successful. I apologize for any errors or omissions.

My thanks to Raviv Kula, Orli Haimee and Dafna Meir for drawing the figures and to Ora Kami, Agrometeorological Unit, !MS, who compiled the first bibliographical list of this book.

I am indebted to the Chancellor, Rector, Dean of the Faculty of Social Sciences and the Research Authority of Bar-Han University; the Ministry of Environment and the Ministry of Agriculture of the State ofIsrael; The Jordan Valley Unit of the Settlement, branch of the World Zionist Union; the Dr. Irvine and Cerana Moskowitz Chair in Land of Israel Studies at Bar-Ian; the Schnitzer Foundation for Research on the Israeli Economy and Society; the President of Israel AMOS Foundation; KKL; the Leon Gottfried Foundation for financial aid to produce the Hebrew edition of this book. I thank them all. July 1996 Yair Goldreich Department of Geography, Bar-Han University Preface to the English Edition

This English edition of this book is an updated and revised version of the Hebrew edition, published in 1998 by Bar-Han University (Ramat Gan) and Magnes (Hebrew University Publishers, Jerusalem). Some 90 new references have been added; many Hebrew references, with parallel references in English were omitted. Some sections, which may be obvious to Israelis (for example, describing the general physiography features of Israel), have been added for the international reader; some of the particularly localized text has been omitted. Since many readers may not find the Hebrew references easily accessible or relevant, the letter (H) has been added to each Hebrew reference. It should be noted however, that many Hebrew journals include an English summary (e.g. Judea Samaria Research Studies) and all the Masters and Ph.D. theses granted at Israeli Universities include expanded English abstracts. A geographical index next to each site, the region number according to Fig. 2.10 (or the geo-climatic map printed on the back cover of the book) was added to assist the reader who is not familiar with the map of Israel. However, names of locations more familiar to the international reader have been used, for example Jerusalem and not Yerushalayim was used. The official Hebrew names (for example Yerushalayim) have been included in square brackets, in the geographical index. The official spelling of locations as appear in the Map of Settlements in Eretz Israel, 1:250,000 (1997), Survey of Israel, Tel Aviv has been used. A list of abbreviations and a micro Hebrew• English dictionary of site names has been included.

I would like to thank my colleagues at the various institutions that assisted me in the completion of the English version of this book, especially I would like to thank those colleagues who critically read and made constructive suggestions for the improvement of sections of the manuscript: Prof. Leonard Druyan (Chapter 3); Prof. Gerald Stanhill (Chapters 5, 6.1, 7.1, 9.2, 9.3) and Prof. Stephen Brenner (most of the remaining chapters).

My thanks to Ms. Sigal Bracha and Mr. Lev Karnibad for converting the drawings from Hebrew to English. My appreciation to Kluwer Academic Plenum Publishers, with special thanks to Dr. Kenneth Howell and Mary Curioli. Without Brenda Idstein, our English Language Editor, this work would never have been accomplished. Her patience and time were invaluable.

January, 2002 Yair Goldreich Department of Geography, Bar-Han University

ix Contents

List of Abbreviations ...... xvii Micro Dictionary of Site Names ...... xvii List of Figures ...... xix List of Photos ...... xxiv List of Tables ...... xxiv

PART I ISRAEL CLIMATOLOGY: OBSERVATION AND RESEARCH

CHAPTER 1 THE HISTORY OF CLIMATE AND METEOROLOGICAL OBSERVATIONS AND RESEARCH IN ISRAEL ...... 3 1.1 Pre-mandate climate observations ...... 3 1.2 British mandate meteorological stations ...... 6 1.3 Israel meteorological stations ...... 8 1.4 Israel climate research ...... 9

CHAPTER 2 CLIMATE REGIONS AND SEASONS IN ISRAEL ...... 12 2.1 Physiography and the location ofIsrael on the world climatic map ...... 12 2.2 Mediterranean climate ...... 12 2.3 Israel climate regions ...... 13 2.3.1 Koppen map ...... 13 2.3.2 Thomthwaite Classification ...... 15 2.3.3 Budyko's aridity index ...... 16 2.3.4 Automated regional division ...... 17 2.3.5 Geo-climatic zones ...... 19 2.4 Seasons in Israel ...... 21

CHAPTER 3 RAINY SEASON (WINTER AND TRANSITIONAL SEASONS) CLIMATE ...... 23 3.1 Mean pressure system ...... 23 3.2 Cyclogenesis regions in the Mediterranean basin ...... 23 3.2.1 Genoa low ...... 24 3.2.2 Saharan low ...... 24 3.2.3 Cyprus low ...... 24 3.3 Depression routes in the Mediterranean Sea ...... 26 3.4 Red Sea trough ...... 26 3.5 Jet stream and jet rainfall ...... 27 3.6 Cold fronts and subsequent cold air masses ...... 28 3.6.1 Cold fronts ...... 31 3.6.2 Cold air masses behind the cold fronts ...... 31 3.6.2.1 Convection lines (post frontal lines) ...... 31

xi xii CONTENTS

3.6.2.2 Benard cells and disorganized convective cells ...... 31 3.6.2.3 Coastal fronts ...... 32 3.6.2.4 Cloud streets ...... 33 3.6.3 Vortices ...... 33 3.6.4. The relationship between cloud systems ...... 34 3.7 Typical winter weather and synoptic conditions ...... 35 3.7.1 Statistics of winter weather classifications ...... 35 3.7.2 Synoptic conditions for rain ...... 39 3.7.3 Transition frequencies from one weather condition to another ...... 40

CHAPTER 4 SUMMER CLIMATE ...... 41 4.1 Mean pressure distribution ...... 41 4.2 The summer paradox ...... 42 4.3 The Persian trough ...... 43 4.4 Summer inversions ...... 44 4.5 Upper inversion spatial distribution ...... 45 4.6 Summer month differences ...... 46 4.7 Daily breeze march and vertical changes on the coastal plain ...... 48 4.8 Spatial distribution of the diurnal circulation over Israel ...... 51

CHAPTER 5 PRECIPITATION ...... 55 5.1 The spatial variation of precipitation ...... 56 5.1.1 Factors affecting spatial variation and relative contribution ...... 56 5.1.2 Orographic influence ...... 58 5.1.3 The latitude component ...... 60 5.1.4 Proximity to the sea and lee side effects ...... 61 5.2 Temporal variations of precipitation ...... 62 5.2.1 Diurnal rainfall distribution ...... 63 5.2.2 Intra-annual rainfall distribution ...... 63 5.2.2.1 Monthly intraseasonal variation ...... 65 5.2.2.2 Other intraseasonal variations ...... 68 5.2.2.3 Wet and dry spells ...... 69 5.2.2.4 Number of rainy days ...... 71 5.2.3 Interannual variation ...... 71 5.2.3.1 Interannual rainfall distribution ...... 72 5.2.3.2 Interannual monthly rainfall distribution ...... 74 5.2.3.3 Rainfall periodicity ...... 75 5.2.3.4 Droughts in Israel ...... 76 5.3 Rainfall intensity ...... 79 5.3.1 Daily amounts ...... 79 5.3.2 Hourly intensities ...... 80 5.3.3 Depth-duration ratios ...... 81 5.4 Solid precipitation and thunderstorms ...... 85 5.4.1 Snow ...... 85 5.4.2 Hail ...... 88 5.4.3 Thunderstorms ...... 91

CHAPTER 6 RADIATION AND TEMPERATURE ...... 92 6.1 Radiation ...... 92 6.1.1 Annual march of solar radiation ...... 92 6.1.2 Daily march of radiation ...... 94 6.1.3 Ultraviolet radiation ...... 94 CONTENTS xiii

6.1.4 Interannual radiation changes ...... 96 6.1.5 Solar radiation spatial distribution ...... 97 6.2 Temperature ...... 97 6.2.1 Mean temperature temporal and spatial distribution ...... 97 6.2.2 Temperature dispersion around the mean ...... 103 6.2.3 Extreme temperatures ...... 105 6.2.4 Frost ...... 108 6.2.5 Degree-days ...... 112 6.2.6 Heat stress ...... 113

CHAPTER 7 EVAPORATION, HUMIDITY, CLOUDINESS, FOG, DEW AND VISIBILITy ...... 118 7.1 Evaporation ...... 118 7.2 Humidity ...... 122 7.2.1 Absolute humidity ...... 122 7.2.2 Relative humidity ...... 123 7.3 Cloudiness and fog ...... 127 7.3.1 Spatial cloudiness and temporal distribution ...... 127 7.3.2 Fog ...... 129 7.4 Dew ...... 130 7.5 Visibility ...... 133

CHAPTER 8 WIND AND SHARA V PHENOMENA ...... 135 8.1 The daily and annual march of wind speed ...... 135 8.2 Strong winds ...... 139 8.2.1 Extraordinary storms ...... 139 8.2.2 Strong winds above certain thresholds ...... 139 8.3 Kadim and sharav ...... 141 8.3.1 Sharav day definition ...... 142 8.3.2 Synoptic sharav conditions ...... 143 8.3.2.1 Sharav depressions ...... 143 8.3.2.2 Red Sea trough sharavs ...... 145 8.3.2.3 Subsidence sharavs ...... 145 8.3.3 Sharav day frequency and distribution ...... 145 8.3.4 Sharav effects ...... 146 8.4 Sand and dust storms ...... 148 8.4.1 Sand and dust storm meteorological conditions ...... 148 8.4.2 Temporal and spatial distribution of dust storms ...... 148 8.4.3 An extraordinary sand and dust storm - November 1958 ...... 151

CHAPTER 9 CLIMATE: PAST, PRESENT AND FUTURE ...... 153 9.1 Geological and historical era climate variation ...... 153 9.1.1 Temperature and precipitation variations ...... 153 9.1.2 The Holocene climate ...... 157 9.1.3 Past atmospheric circulation reccnstruction ...... 161 9.2 Contemporary long-term variability ...... 162 9.3 Future climate ...... 166 xiv CONTENTS

PART II ISRAEL: APPLIED CLIMATOLOGY

CHAPTER 10 CLIMATIC FORECAST ...... 173 10.1 Short-range climate forecasting ...... 173 10.2 Long-range forecasting (seasonal rainfall forecasting) ...... 176 10.2.1 Teleconnection forecasting ...... 177 10.2.2 In situ seasonal forecasting using the seasonal onset data ...... 177 10.2.3 Teleconnection forecast using seasonal onset data ...... 178 10.2.4 Mixed forecast using seasonal onset data ...... 179

CHAPTER 11 PRECIPITATION ENHANCEMENT ...... 182 11.1 Cloud seeding ...... 182 11.1.1 Israel I experiment (1961-1967) ...... 184 11.1.2 Israel II experiment (1969-1975) ...... 185 11.1.3 Israel III experiment (1975-1995) ...... 189 11.1.4 Effects of seeding on the spatial precipitation variation ...... 191 11.1. 5 Cloud seeding in Israel: Interim conclusions ...... 193 11.2 Mediterranean water surface mixing ...... 195

CHAPTER 12 URBAN CLIMATE AND AIR QUALITY ...... 198 12.1 Urban climate ...... 198 12.1.1 Urban temperature ...... 198 12.1.2 Urban influences on rainfall ...... 199 12.1.2.1 Checking normals and trend tests ...... 199 12.1 .2.2 Using regression analysis for checking the urban influence ...... 200 12.1.2.3 The Greater Haifa urban influence of on rainfall ...... 201 12.1.2.4 The Jerusalem urban influence of on rainfall ...... 201 12.1.2.5 Causes for excess urban rainfall ...... 202 12.2 Air quality ...... 202 12.2.1 Potential air pollution ...... 203 12.2.1.1 Mixing depth layer ...... 204 12.2.1.2 Poor ventilation conditions ...... 206 12.2.1.3 Synoptic conditions for potential air pollution ...... 207 12.2.2 Smog ...... 208 12.2.3 Acid rain ...... 209

CHAPTER 13 CLIMATE AND PLANNING ...... 211 13.1 Agroclimatology ...... 211 13.2 Settlement planning ...... 213 13.2.1 Regional planning ...... 215 13.2.2 Town and neighborhood location and planning ...... 215 13.2.3 Building design ...... 218 13.2.4 Wind stress on buildings ...... 221 13.3 Industry location ...... 221 CONTENTS xv

CHAPTER 14 CLIMATE AND AL TERNATIVE ENERGY ...... 225 14.1 Solar energy ...... 225 14.2 Wind energy utilization ...... 226 14.2.1 Mean wind speed ...... 227 14.2.2 Wind speed assessment by topoclimate surveys ...... 229 14.2.3 Establishment of turbines and wind farms ...... 230 14.3 Energy towers ...... 231

APPENDIXES

Appendix 1 ...... 232 Appendix 2 ...... 233

REFERENCES ...... 234

GLOSSARY ...... 251

Authors index ...... 256

Geographical index ...... 260

Subject index ...... 264 Abbreviations

AGL - above ground level NOAA - National Oceanic and Atmospheric AMS - American Meteorological Society Administration AMI - Israeli Meteorological Union PAP - potential air pollution AP - airport PS - power station ASL - above sea level ppm - part per million BP - before present R. -River cm - centimeter RH - relative humidity CC - correlation coefficient(s) RP - return period CCN - cloud condensation nuclei s - second cgs - centimeter, gram, second (the old physical units SD (or 0) - standard deviation system) SE - standard error DI - discomfort index SI - Systeme international (the new physical units system• DVI - dust veil index m, kg, second, which replace the c.g.s. system) dPa - deca-Pascal SST - sea surface temperature ECMWF - European Center for Medium-Range Weather UTC - Universal Coordinated Time Forecasting UV - ultra-violet GCM - global circulation model WMO - World Meteorological Organization g - gram 2-D - two dimensions gpm - geopotential meter 3-D - three dimensions h - hour hPa - hecto-Pascal Micro-dictionary of site names HDD - heating degree day Be'er- well IMS - Israeli Meteorological Service Bet (or Beit in Arabic) - house of IN - ice nuclei En - spring (fountain) INU - Index of Nonuniformity Gan- garden IR - infrared Gesher - bridge ITC - inter tropical convergence Giv'at - hill of LST - local standard time Gush- block k - thousand; kilo Ha-the ka - k years (kilo annum calendar year) Kefar - village km - kilometer Ma'ale - ascent KW - Kilowatt Nahal- river M - million; mega Newe - home of (or oasis) m -meter Nir - ploughed field min.- minute Rarnat - plateau of mm - millimeter Rosh-head MJ - mega-joule Sede - field of MW - megawatt Tel-hill of NASA - National Aeronautics and Space Administration Tirat - fort of

xvii LIST OF FIGURES

Figure 1.1 Exner annual rainfall map (isohyets - cm). Rainfall depth presented in mm by station ...... 5 Figure 1.2 The settlements, in 1920, with rain gauges ...... 7 Figure 1.3 Meteorological stations increase ...... 9

Figure 1.4 Rain gauge stations in 1970 ...... 10 Figure 2.1 Koppen climatic classification ofIsrael ...... 13 Figure 2.2 Global distribution of Koppen Mediterranean climate ...... 14 Figure 2.3 Sea level mean pressure (bPa) for January ...... 14

Figure 2.4 Sea level mean pressure (bPa) for July ...... 14 Figure 2.5 Moisture index (1955 version) of the Thornthwaite climatic classification ofIsrael ...... 15 Figure 2.6 Budyko climatic classification ofIsrael...... 16 Figure 2.7 Cluster analysis for 41 climatic stations ...... 18 Figure 2.8 COPLOT analysis for six variables ...... 19 Figure 2.9 Automated climatic zones, according to the COPLOT analysis ...... 19 Figure 2.10 Geo-climatic regions ...... 20 Figure 2.11 The four season cycle and the annual march of three climatic variables ...... 21 Figure 3.1 A schematic model showing a dynamic (cold) low at surface level and an upper air trough ...... 24 Figure 3.2 Low routes of the Mediterranean Basin ...... 24 Figure 3.3 An isobar map, at 3 km, with surface fronts show an Alps lee depression ...... 24

Figure 3.4 Low routes and cyclogenesis regions located over the Mediterranean Basin during winter and transitional seasons ...... 25 Figure 3.5 Mean monthly wind speed (knots) in the upper troposphere at Bet Dagan ...... 27 Figure 3.6 A typical jet stream situated over the Middle East ...... 28 Figure 3.7 An inverse jet stream situated over the Middle East ...... 28 Figure 3.8 Synoptic surface chart of the eastern Mediterranean ...... 28 Figure 3.9 A schematic illustration during a typical synoptic situation of rainfall in the Middle East of the various spatial cloud structures ...... 29 Figure 3.10 The relative rainfall contribution (%) of cloud systems ...... 31 Figure 3.11 A schematic model showing the creation ofa coastal front near the Israeli coast...... 35 Figure 3.12 Location of weather types for the central coastal plain, by a generalized synoptic situation ...... 37

Figure 3.13 A schematic westerly wavy zonal flow along the Mediterranean ...... 38 Figure 3.14 Three upper air trough (500 bPa) schematic situations ...... 39 Figure 4.1 Mean June-September 1000 bPa height contours ...... 41 Figure 4.2 Noon upper inversions parameters over Bet Dagan ...... 44 Figure 4.3 Noontime temperature and RH profiles over Bet Dagan and Jerusalem July 9, 1973 ...... 46 xix xx LIST OF FIGURES

Figure 4.4 Ground and upper noontime air temperature profiles over Bet Dagan and Jerusalem July 9, 1973 ...... 47 Figure 4.5 Wind speed and direction, computed by a numerical model, over a plain at 30° latitude, at 4 and 14 Ian from the sea ...... 50 Figure 4.6 Wind speed and direction, computed by a numerical rr.odel, over a plain at 30° latitude, at 4 and 14 Ian from the sea. Based on westerly and northwesterly 4 mls geostrophic-etesian wind, and 14 Ian from the sea start a 400 m hilly area ...... 50 Figure 4.7 Three hour wind rose in the Ela Valley (July 1982) ...... 50 Figure 4.8 Some pilot balloon course over Ela Valley July 18-19, 1982 and August 18-19, 1982 ...... 51 Figure 4.9 Time-height section of the wind field over the Ela Valley (July 18-19, 1982) ...... 51 Figure 4.10 The same as Fig. 4.9 for July 18-19, 1982 ...... 52 Figure 4.11 A schematic block diagram of the three levels of generalized winds ...... 52 Figure 4.12 Mean July streamlines at 1100 ...... 53 Figure 4.13 Mean J ul y streamlines at 1700 ...... 53 Figure 4.14 Mean July streamlines at 23 00 ...... ·...... ··· .. 53

Figure 4.15 Mean July streamlines at 0200 ...... ·...... ·.... ·.... ·· .... ·· ..· ...... ·· ...... ·· ...... ··· ...... ·.. ·.. ·...... 53

Figure 5.1 Precipitation (mm) map of standard normals for the periods, 1961-90 ...... 56 Figure 5.2 Isohyet (mm) map of two standard normals of the central coastal plain ...... 61 Figure 5.3 Mt. Karmel rainfall anomaly ...... 64 Figure 5.4 Diurnal curve of high and low Negev rainfall intensitit:s ...... 65 Figure 5.5a Monthly rainfall distribution (upper) and accumulated rainfall (lower) in Hafez Hayyim, 1961-90 ...... 65 Figure 5.5b Monthly accumulated rainfall frequency in Tel Aviv and in Jerusalem 1961-90 ...... 65 Figure 5.6 Midseason isochrones map for 1961-90 according to the first harmonic peak ...... 66 Figure 5.7 Explained variance (%) of the midseason date for 1961-90 ...... 66 Figure 5.8 Mean rainfall daily distribution in En HaHoresh for 1958/9-1977/8 ...... 69 Figure 5.9 Mean rainfall ten days distribution in Hafez Hayyim, 1961-90 ...... 69 Figure 5.10 Annual rainfall in Jerusalem ...... 73 Figure 5.11 Annual rainfall frequency distribution for 116 years in Jerusalem, 30 mm intervals ...... 74

Figure 5.12 Coefficient of variation (%) of rainfall for 1931-1970 ...... 75 Figure 5.13 Annual rain (%) above given intensity thresholds ...... 82 Figure 5.14 Maximal hourly rainfall depth (mm) for a 10 year RP ...... 84 Figure 5.15 Maximal six hours rainfall depth (mm) for 10 years RP ...... 86

Figure 5.16 A chart for determining RP coefficients (%), according to the RP (years) ...... 87 Figure 5.17 Maximal rainfall intensities probabilities for a given duration in Negba ...... 87 Figure 5.18 Maximal daily rainfall probabilities (mm) above given intensities in Negba ...... 88 Figure 5.19 Synoptic map for the great snow day (February 6, 1950) ...... 90 LIST OF FIGURES XXI

Figure 5.20 Annual isoceraunic map (number of thunderstorm days) ...... 90 Figure 6.1 Mean daily solar radiation for Be'er Sheva ...... 94 Figure 6.2 Global and normal radiation mean at 11°°_lilO in Be'er Sheva ...... 94 Figure 6.3 Bet Dagan and Jerusalem Airport mean illumination duration ...... 95 Figure 6.4 Global radiation diurnal curve ...... 95 Figure 6.5 Daily radiation balance at Bet Dagan 1967-1968 ...... 96 Figure 6.6 Jerusalem (Giv'at Ram) global ultraviolet daily march of radiation 1991-1992 ...... 96 Figure 6.7 Interannual summer daily global radiation variations 1964-1973 ...... 98 Figure 6.8 Greater Tel Aviv Air pollution influence on Bet Dagan radiation on a bright day ...... 98 Figure 6.9 Mean temperature distribution ...... 99 Figure 6.10 Mean temperature differences ...... 102 Figure 6.11 Mean minimum and maximum temperature standard deviations 1955-1964 ...... lO3 Figure 6.12 Mean cold nights ...... 105 Figure 6.13 Mean annual number of hours with temperatures below 7.20 ...... 108 Figure 6.14 Variation, with elevation, of three chilling temperature thresholds ...... lO9 Figure 6.15 Annual heating degree-day values for 18.50 threshold, 1974-1983 ...... 112 Figure 6.16 Medium and heavy heat stress, daily mean hours ...... 114 Figure 6.17 Heavy sharav inconvenience index ...... 115 Figure 7.1 Class A pan annual evaporation (cm) map ...... 119 Figure 7.2 Annual evaporation/rainfall ratio in geometrical intervals ...... 121 Figure 7.3 Mean annual vapor pressure (dPA) ...... 122

Figure 7.4 Mean annual relative humidity (%) ...... 123 Figure 7.5 Kefar Tabor and Elat mean relative humidity annual march ...... 125 Figure 7.6 Tel Aviv (HaQirya and AP stations) mean relative humidity annual march ...... 125

Figure 7.7 A2/AI distribution in a geometric interval ...... 127 Figure 7.8 Mean annual cloudiness (%) map ...... 128 Figure 7.9 Mean annual dewy nights map ...... 129 Figure 7.10 June-September daytime visibility multiannual variation means, at Lod Airport ...... 133 Figure 7.11 June-September daytime visibility multi annual variation means, for certain ranges, at Lod Airport ...... 134

Figure 8.1 Mean, monthly mean maximum, absolute maximum wind speed (mls) daily march at Hafez Hayyim ...... 136

Figure 8.2 Mean annual, monthly wind speed (mls) daily march in Gaza ...... 136 Figure 8.3 The maximum wind speed hour for various Negev stations ...... 137

Figure 8.4 Mean annual, monthly wind speed (mls) daily march at Mizpe Shalem ...... 137 Figure 8.5 Mean wind speed annual march in various stations ...... 138 xxii LIST OF FIGURES

Figure 8.6 Strong winds (>29km/h [-8 mls]) annual frequency daily march, by wind directions in Kefar Blum ...... 140 Figure 8.7 Schematic synoptic conditions (isobars and wind directions) during sharav conditions ...... 143 Figure 8.8 Annual march ofsharav days in Tel Aviv and Jerusalem ...... 145 Figure 8.9 Factors causing sand storms and their influence on winds ...... 149

Figure 8.10 Annual dust deposition quantities (g/m2) •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• •• 151 Figure 9.1 Climate changes in Israel over the last 10 ka after various sources ...... 158 Figure 9.2 Precipitation and Dead Sea level variability between 2,000 B.C.E to 1,115 C.E ...... 160 Figure 9.3 Precipitation and Dead Sea level variability between 1100 C.E. to 1980 C.E ...... 160 Figure 9.4 Precipitation and Dead Sea level variability between 1800 C.E. to 1980 C.E ...... 160 Figure 9.5 Atmospheric circulation at the end of the Late Pleistocene ...... 162 Figure 9.6 Atmospheric circulation at the Neolithic (8,000-6,000 B.C.E.) period ...... 162 Figure 9.7 Atmospheric circulation during the Chalcolithic and early Bronze (4,500-2,500 B.C.E.) periods ...... 162 Figure 9.8 Mean decade temperature for Jerusalem (December-March) and England (December-February) ...... 162 Figure 9.9 West-east vertical cross section schematic illustration of effects of influencing land-use parameters on the base of the upper inversion height ...... 166 Figure 9.10 Annual march of global temperature since 1958, and extrapolation to year 2020 according to the three scenarios ...... 167 Figure 9.11 Annual rainfall deviation from the normal at Jerusalem ...... 169 Figure 9.12 Annual rainfall deviations from the normal (years following a volcanic eruption) at Jerusalem and the DVI ...... 169 Figure 10.1 Nomogram for predicting minimum temperature. From the 1700 wet-bulb temperature to the predicted minimum temperature ...... 175 Figure 10.2 October upper trough axis mean location (500 hPa) over the Mediterranean Sea ...... 179 Figure 10.3 October upper trough axis mean location (500 hPa) along 35°N versus change of height surface between trough and a position 30° westward, along 400N latitude ...... 179 Figure 10.4 October upper trough axis mean location (500 hPa) along 35°N as compared to the Atlantic trough ...... 179 Figure 11.1 A typical cumulus congestus cloud in January ...... 182 Figure 11.2 Israel I experiment (1961-67) seeding plan and target areas ...... 185 Figure 11.3 Israel II experiment (1961-67), operational seeding plan and various seeding lines and target areas ...... 186 Figure 11.4 Composite correlation map for the central target area for seeded days and unseeded days for the Israel I experiment period ...... 191 Figure 11.5 Location of rainfall centers by seeding period in the North ...... 192 Figure 11.6 Location of the rainfall centers (subsamples) for the three seeding periods ...... 192 Figure 11.7 Monthly mean (1961-2) temperature profiles in the eastern Mediterranean Sea ...... 195 LIST OF FIGURES xxiii

Figure 12.1 Double mass curves for Ramat HaSharon (urban downwind station) as compared to two rural stations ...... 200 Figure 12.2 Residual map (in mm) of the annual rainfall normals (1961-60) ...... 201 Figure 12.3 Mixing depth median annual march ...... 204 Figure 12.4 Mixing layer depth: Temporal and spatial variation across the country, on a typical summer day (17.6.87) ...... 205 Figure 12.5 Schematic atmospheric condition model for fumigation and looping plumes ...... 206 Figure 12.6 Mean number of days with no rainfall and bad air ventilation «7 knots) in 13 anemometer stations ...... 207

Figure 12.7 Wind speed percentages below 7 knots in Lod at 1400 ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 207 Figure 12.8 The correlation between the number of vehicles and the maximal ozone concentrations in Jerusalem ...... 210 Figure 13.1 Number of hours at optimum temperatures for the budding of citrus flowers December-January ...... 212 Figure 13.2 The influence of climate factors on planning stages ...... 214 Figure 13.3 Climatic planning proposal for the middle Jordan Valley and the northern Dead Sea coast...... 216 Figure 13.4 Ma'ale Adummim - topographical cross section, topographical map (50 m interval) of the region and climatic data ...... 217 Figure 13.5 A suggested roof, which allows winter solar radiation ...... 218 Figure 13.6 A rectangular shaped house with the long front facing south and north versus east & west...... 218 Figure 13.7 Be'er Sheva, February and August 1963 wind polygons ...... 223 Figure 13.8 Ashdod wind direction frequency and accumulated pollutant concentration (pollution rose) as a function of wind direction ...... 223 Figure 13.9 Ashdod master plan with two optimal industrial zones ...... 224 Figure 13.10 Be' er Sheva wind direction frequency and accumulated pollutant concentration (pollution rose) as function of wind direction ...... 224 Figure 14.1 Mean daily wind speed annual march in Tel Qatif as compared to the mean daily electricity load in 1988 ...... 227 Figure 14.2 Daily wind speed march in Tel Qatifas compared to the mean electricity load in winter 1988 ...... 227 Figure 14.3 Daily wind speed march in Tel Qatifas compared to the mean electricity load in summer 1988 ...... 227 Figure 14.4 Electricity production by wind speed distribution ...... 227 Figure 14.5 Hourly wind speed frequency distribution in Mt. Mirbaz and its Weibull curve ...... 228

Figure 14.6 Mean annual wind speed (mls) ofIsrael...... 228

Appendix 2 Basic wind velocity (mls) map for structure planning in Israel...... 233 List of Photos

Photo 1.1 Dr. Abraham Baruch, the first active Jewish meteorologist in the Land ofIsrael...... 6 Photo 1.2 Professor Dov Ashbel, the Israeli climatologist of the 20th century ...... 8 Photo 3.1 Army satellite image (December 5, 1977 at 10°7) in visible wavelength, during a typical synoptic situation of rainfall in the Middle East: Cyprus low northwest of Cyprus ...... 30

Photo 3.2 Infra Red image (lR) of water vapor (6.3 Il) and thermal IR image (11 Il) of the Middle East snowfall on Jan. 1, 1992 ...... Book cover Photo 3.3 Thermal IR image and visible image channel of the eastern Mediterranean on the eve of the great hail, Feb. 23, 1992 ...... Book cover Photo 6.1 Kibbutz Sa'ar avocado plantation giant ventilator ...... 111 Photo 11.1 A ground cloud seeding generator in Ayyelet HaShahar...... 184 Photo 11.2 Cloud research airplane and cloud seeder airplanes with rain radar and the EMS offices at Lod Airport in the background ...... 185 Photo 11.3 Rainfall radar image showing a cold front approaching the Israeli coast...... 188 Photo 13.1 Mizpe Ramon neighborhood planning model by the architect, Arieh Rahamimoff...... 217 Photo 13.2 Supreme Court building with its shaded inner courtyard in Jerusalem ...... 219

Photo 13.3 The climatically planned Jordan Valley Regional Cou~cil Building ...... 220 Photo 13.4 Passive heating and cooling house in Sede Boqer ...... 221 Photo 14.1 Solar energy absorbing systems at the Hillel Yaffe Hospital in Hadera ...... 225 Photo 14.2 Photovoltaic cells in Had Nes in the Golan Heights ...... 226 Photo 14.3 Using wind for pumping water at Be'er Menuha in the Arava ...... 226 Photo 14.4 Negev wind observations, near the Mizpe Ramon observatory ...... 229 Photo 14.5 A Golan Heights wind farm ...... 231

List of Tables

Table 1.1 Meteorological station operation (mainly rainfall stations) for various periods ...... 8 Table 2.1 Moisture index according to the two Thornthwaite (1948 and 1955) versions ...... 15 Table 2.2 Comparison of various climatic classifications ofIsrael ...... 17 Table 3.1 Summary of rainfall cloud system characteristics ...... 36 Table 3.2 Frequency and order of transition between cloud systems ...... 36 Table 3.3 Weather classification and frequency ...... 37 Table 3.4 Transition frequency from one weather condition to another on the next or previous day ...... 38 Table 4.1 Number of inversion days ...... 45 Table 4.2 Bet Dagan basic upper inversion height frequency, four daily observations during four summer months ...... 45 xxiv LIST OF TABLES xxv

Table 4.3 Mean temperature differences between Beer Sheva and Mediterranean Sea surface temperature near the coast...... 48 Table 4.4 Mean ground temperature at 5 cm depth for three daily observations ...... 48 Table 5.1 Mean annual rainfall (mm) in some European cities ...... 55 Table 5.2 Rainfall contribution to the mean annual rainfall ...... 57 Table 5.3 The influence of sea proximity for Yizre'el Valley location ...... 61 Table 5.4 Precipitation (mm) normals for 1961-1990 ...... 67 Table 5.5 Ronberg's classification (%) of active and settled days in active and settled subperiods ...... 69 Table 5.6 Jerusalem mean rainfall distribution (mm), number of rain spells, number of rainy days and daily rain amount per spell, four rainfall groups per rain spell (q in mm) for 1951-1970 ...... 70 Table 5.7 Mean daily amount (mm) and hourly intensity (mm/hr) as a function of rain spell duration ...... 70

Table 5.8 Mean number of rainfall days and coefficient of variation for four stations, 1939/40-1953/4 ...... 72 Table 5.9 Jerusalem rainfall distribution in five intervals ...... 73 Table 5.10 The maximum value of the monthly rainfall amount ...... 76

Table 5.11 Additional monthly rainfall per 10 drop in monthly temperature. The comparative monthly rainfall increase (%) ...... 76 Table 5.12 Monthly rainfall normal, relative variability and coefficient of variation for three rainfall stations ...... 78

Table 5.13 Daily rainfall frequency distribution (%) for 25 years in Tel-Aviv ...... 78 Table 5.14 Mean monthly rainfall depth, number rainfall days and mean rainfall days above various thresholds for 25 rainfall years in Tel-Aviv ...... 80

Table 5.15 Monthly convective rainfall (>30 mm1hr) distribution (%) in various stations ...... 82 Table 5.16 Values ofn for various mean rainfall series ...... 83 Table 5.17 Values of n for depth-duration-probability curve rainfall series ...... 87 Table 5.18 Relative rainfall depth coefficient and return period coefficients for various rainfall stations ...... 88 Table 5.19 Total Jerusalem snow days for 1939-1972 ...... 89 Table 5.20 Necessary temperature thresholds for snow fall in Jerusalem ...... 89 Table 5.21 Mean characteristic comparisons at 500 hPa level for rain and snow days ...... 89 Table 5.22 Total hail events and hail day hourly observations for 18 years at Lod ...... 90 Table 6.1 Mean monthly and annual daily global radiation. Radiation percentages in Jerusalem compared to radiation outside the atmosphere ...... , ...... 93 Table 6.2 Ultraviolet radiation exposure time (min.) needed for an erythema dose ...... 97 Table 6.3 Average daily temperature, maximum and minimum for select stations ...... 101 Table 6.4 Monthly mean hourly temperature frequency distribution in three stations ...... 104 Table 6.5 National and regional mean temperature standard deviations ...... 104 Table 6.6 Absolute maximum temperature for various stations ...... 106 Table 6.7 Absolute minimum temperature for various stations ...... 107 Table 6.8 Threshold damage from negative temperatures in select orchards ...... 110 xxvi LIST OF TABLES

Table 6.9 Number of frost nights for five years (1957-1962) ...... 110 Table 6.10 Number of cases and frequency of low temperatures in a Bet Dagan weather screen ...... 110 Table 6.11 Mean heating degree-days (under 18.5°) in select stations ...... 113 Table 6.12 Thorn discomfort index adapted for Israel...... 114 Table 6.13 Number of hours (mean per day) of heat stress ...... 116 Table 7.1 Monthly (mm) and annual (cm) pan Class A evaporation ...... 120

Table 7.2 Mean national relative monthly evaporation (isomers) and the mean relative deviation ...... 120 Table 7.3 Average daily vapor pressure (dPa), maximum and minimum for select stations ...... 124 Table 7.4 Average daily relative humidity (%), maximum and minimum for select stations ...... 126

Table 7.5 Number of fog nights for 1951-1960 ...... 129 Table 7.6 Number of dewy nights in various stations ...... 132 Table 7.7 Dew amounts (mm) for various stations ...... 132

Table 8.1 Number of stormy days in Israel; days where wind speed was >50 km/h during 10 minutes ...... 139 Table 8.2 Maximal wind speed (knots) values for stormy days ...... 140 Table 8.3 Distribution of mean strong wind speed (km/h) number of hours from the eastern and western section of Geva Karmel ...... 141 Table 8.4 Sharav day definitions ...... 142 Table 8.5 Agroclimate sharav definition ...... 142

Table 8.6 Sharav low characteristics compared to Mediterranean winter lows ...... 144 Table 8.7 Spring month sharav frequencies (Table 8.5 definitions) for Lod, 1938-1990 ...... 146 Table 8.8 Multiple correlation coefficient between spring sharav and winter precipitation temperature ...... 146 Table 8.9 Monthly dust storm distribution for Be'er Sheva by visibility thresholds ...... 150 Table 8.10 Distribution event of dust storms in Be' er Sheva according to wind speed and visibility threshold ...... 150

Table 9.1 Chronology of historic and prehistoric periods in the Land ofIsrael ...... 156 Table 9.2 Temperature and precipitation variation in Jerusalem and sea level temperature (Global mean) ...... 163 Table 9.3 Precipitation and SD (mm) in Miqwe yisrael ...... 163 Table 9.4 The 12 greatest volcanic eruptions (according the DVI) since the start of Jerusalem rainfall measurements ...... 168 Table 10.1 Verification of discriminant function (DF) of rainfall forecasting according to January 1981 data ...... 174 Table 10.2 Timetable of frost forecasting services ...... 176 Table 10.3 Seasonal rainfall forecast according to November rainfall...... 178 Table 11.1 Number of ice crystals per 10 liters in a typical cumulus congestus cloud ...... 183 Table 11.2 Results of the statistical test of Experiment Israel II in the North ...... 187 Table 11.3 Results of the statistical test of Experiment Israel II in the Center and South ...... 189 LIST OF TABLES xxvii

Table 11.4 DRR values for target-control and radiosonde data for separation to dusty days and dustless days in Experiments Israel II & 111...... 190 Table 11.5 Multiple correlation coefficients (R) for the Israel I & II experiment periods, for seeded and unseeded days ...... 192 Table 12.1 Annual rainfall percentage above a certain intensity threshold ...... 199 Table 12.2 Correlation and regression coefficients for various rain periods ...... 201 Table 12.3 Number of synoptic situations events causing air pollution in Israel by season ...... 208 Table 12.4 Mixing depth (m), standard deviation (cr, m) number of observations by synoptic situation ...... 209 Table 13.1 Computed maximal wind speed (m/sec) by a series of24 years for Elat...... 213 Table 14.1 Mean annual (1988) wind speed (m/sec) near five wind turbine sites ...... 230 Appendix 1 Maximal pollutant concentration permitted by hazard prevention Law State Records ...... 232 THE CLIMATE OF ISRAEL OBSERVATION, RESEARCH AND APPLICATIONS