מאמרים

מרכז הידע הישראלי להערכות לשינויי אקלים
2011

A double-resolution transient RCM climate change

A double-resolution regional experiment on hydrodynamic simulation of climate over the eastern Mediterranean (EM) region was performed using an International Center for Theoretical Physics, Trieste RegCM3 model. The RegCM3 was driven from the lateral boundaries by the data from the ECHAM5/MPI-OM global climate simulation performed at the MPI-M, Hamburg and based on the A1B IPCC scenario of greenhouse gases emission. Two simulation runs for the time period 1960-2060, employing spatial resolutions
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

Warming and drying of the eastern Mediterranean: Additional evidence from trend analysis

The climate of the eastern Mediterranean (EM), at the transition zone between the Mediterranean climate and the semi-arid/arid climate, has been studied for a 39-year period to determine whether climate changes have taken place. A thorough trend analysis using the nonparametric Mann-Kendall test with Sen's slope estimator has been applied to ground station measurements, atmospheric reanalysis data, synoptic classification data and global data sets for the years 1964–2003. In addition, changes in atmospheric regional patterns between the first and last twenty years were determined by visual comparisons of their composite mean. The main findings of the analysis are: 1) changes of atmospheric conditions during summer and the transitional seasons (mainly autumn) support a warmer climate over the EM and this change is already statistically evident in surface temperatures having exhibited positive trends of 0.2–1°C/decade; 2) changes of atmospheric conditions during winter and the transitional seasons support drier conditions due to reduction in cyclogenesis and specific humidity over the EM, but this change is not yet statistically evident in surface station rain data, presumably because of the high natural precipitation variance masking such a change. The overall conclusion of this study is that the EM region is under climate change leading to warmer and drier conditions.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2010

Links between the rainfall regime in Israel and location and intensity of Cyprus lows

The interannual variations and the spatial distribution of rainfall in the Mediterranean and semi-arid regions of Israel are analysed with respect to variations in the occurrence of the typical synoptic systems of the Eastern Mediterranean. The synoptic analysis is based on a daily, semi-objective synoptic classification (Alpert et al., 2004a). The study covers the months November–March, in which 90% of the annual rainfall is obtained, mostly resulting from Cyprus lows. The interannual variations of the rainfall are well explained by the synoptic types, and the occurrences of Cyprus lows are highly correlated with the rainfall. It was found that the daily and seasonal rainfall are highly dependent on the depth of the cyclone. Moreover, deep lows are more effective for the mountainous regions, due both to the enhanced orographic effect and to the fact that stronger winds, associated with deep lows, are more efficient in transporting rain-producing clouds from the Mediterranean Sea inland. The location of the cyclone determines the spatial distribution of the rain it produces over Israel. The cyclones located east of Cyprus were found productive mainly for the southern parts of the study region, while those located to the west and north of Israel were found productive for the north of the country. The high sensitivity of the rainfall to the location of the surface cyclones emphasizes the major role that lower level moisture transport plays in rain formation.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2010

Numerical simulation of seasonal distribution of precipitation over the eastern Mediterranean with a RCM

Regional climate model (RCM) RegCM3 with 50 km horizontal resolution driven from the lateral boundaries by the data from NCEP/NCAR re-analysis is used in a series of ten climate downscaling experiments over the eastern Mediterranean (EM) region. Results of the experiments are characterized by seasonal precipitation patterns with notable offshore precipitation zones positioned ~50 km westward of a less intense precipitation zone over the coastal area. Atmospheric processes determining the distribution of seasonal precipitation patterns in the EM are analyzed based on results of the RCM experiments performed. Level of success of the model representation of the actual precipitation over the ECM appears to be depending on that of precipitation balance over different parts of the domain. Excessive moisture convergence over a sub-area usually takes place at the expense of moisture divergence from neighboring areas. Synoptic mechanism causing formation of the precipitation zone in the offshore zone appears to be associated with the role of meridionally oriented atmospheric trough systems extending from Scandinavia or Siberia to the EM during the period with rainy events. In such situations, air flows with strong northern components lead to intense transport of cold air masses to the EM. Meeting of the cold air masses the warm and humid air over the sea surface in the offshore zone causes formation of persistent squall lines and heavy rains there. Such processes may continue quite long as long as the troughs are stationary.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2010

Factors governing the interannual variation and the long-term trend of the 850 hPa temperature over Israel

This study examines the ability of the interannual variability in the occurrence of synoptic types, intensity of large-scale circulations and global temperature to explain that of the 850 hPa temperature in Israel for the summer and the winter. The synoptic factor was represented by 19 types defined by Alpert et al(2004b). For the summer, the deep and the weak Persian Trough explained 35% of the interannual temperature variance. For the winter, the lows to the east and to the north explained 44% of the interannual temperature variance. Two additional factors were incorporated: large-scale circulations, the North Atlantic Oscillation for the summer and the Arctic Oscillation for the winter; and global radiative forcing, represented by the global temperature. Both of them were found to be significant, and the variance explained by all of them is 56% for the summer and 64% for the winter. In the summer the variation is dominated by warm and cool types whereas in the winter the cold systems dominate.The individual contribution of each factor to the long-term temperature trend was estimated. While the global radiative forcing contribution was positive and large in both seasons, the synoptic contribution was positive, four times larger in the summer. The large-scale contribution was negative, three times larger in the winter. The considerable warming in the summer results from a rapid increase in the occurrence of the weak Persian Trough, which is a warm type. The study approach may be useful for predicting future temperature regimes, based on predicted synoptic features in climatic models.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2010

Factors governing the interannual variation and the long-term trend of the 850 hPa temperature over Israel

his study examines the ability of the interannual variability in the occurrence of synoptic types, intensity of large-scale circulations and global temperature to explain that of the 850 hPa temperature in Israel for the summer and the winter. The synoptic factor was represented by 19 types defined by Alpert et al(2004b). For the summer, the deep and the weak Persian Trough explained 35% of the interannual temperature variance. For the winter, the lows to the east and to the north explained 44% of the interannual temperature variance. Two additional factors were incorporated: large-scale circulations, the North Atlantic Oscillation for the summer and the Arctic Oscillation for the winter; and global radiative forcing, represented by the global temperature. Both of them were found to be significant, and the variance explained by all of them is 56% for the summer and 64% for the winter. In the summer the variation is dominated by warm and cool types whereas in the winter the cold systems dominate.The individual contribution of each factor to the long-term temperature trend was estimated. While the global radiative forcing contribution was positive and large in both seasons, the synoptic contribution was positive, four times larger in the summer. The large-scale contribution was negative, three times larger in the winter. The considerable warming in the summer results from a rapid increase in the occurrence of the weak Persian Trough, which is a warm type. The study approach may be useful for predicting future temperature regimes, based on predicted synoptic features in climatic models
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2007

European Atmospheric Pollution Imported by Cooler Air Masses to the Eastern Mediterranean during the Summer

In this study we combine Pb isotopes, Pb, Ni, Cu, Zn, and several major metal concentrations, identification of the aerosol particles, and synoptic and back trajectory analyses to obtain direct evidence for the extent and nature of mixing between Middle Eastern and European sources emissions of metals and aerosols. During the summer months aerosols collected in Israel are highly polluted by metals (EF(Ni) = 120, EF(Cu) = 320, EF(Zn) = 30, EF(Pb) = 540; average values). The fraction of European Pb of mostly industrial sources is 61 +/- 21% in Jerusalem, and the fraction of European Cu, Zn, Ni, and aerosols should be on the same order. Whenever a steep pressure gradient is built between the barometric trough originating from the Persian Gulf and the subtropical ridge along the African coast, stronger westerly winds and cooler temperatures (deep Persian Trough) prevail overthe Middle East, and higher amounts of European pollution are observed in the atmosphere (74 +/- 13%). On the other hand, when the Persian Trough is in its shallow mode, the proportion of European pollution is lower (45 +/- 18%, based on Pb isotopes). This study demonstrates that atmospheric pollution over the East Mediterranean region during the summer is influenced not only by local atmospheric dispersion conditions but also by the ability of the atmosphere to inherit a significant proportion of pollutants from European sources.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2003

Late Holocene climates of the Near East deduced from Dead Sea level variations and modern regional winter rainfall

The Dead Sea is a terminal lake of one of the largest hydrological systems in the Levant and may thus be viewed as a large rain gauge for the region. Variations of its level are indicative of the climate variations in the region. Here, we present the decadal- to centennial-resolution Holocene lake-level curve of the Dead Sea. Then we determine the regional hydroclimatology that affected level variations. To achieve this goal we compare modern natural lake-level variations and instrumental rainfall records and quantify the hydrology relative to lake-level rise, fall, or stability. To quantify that relationship under natural conditions, rainfall data pre-dating the artificial Dead Sea level drop since the 1960s are used. In this respect, Jerusalem station offers the longest uninterrupted pre-1960s rainfall record and Jerusalem rains serve as an adequate proxy for the Dead Sea headwaters rainfall. Principal component analysis indicates that temporal variations of annual precipitation in all stations in Israel north of the current 200 mm yr−1 average isohyet during 1940–1990 are largely synchronous and in phase (∼70% of the total variance explained by PC1). This station also represents well northern Jordan and the area all the way to Beirut, Lebanon, especially during extreme drought and wet spells. We (a) determine the modern, and propose the past regional hydrology and Eastern Mediterranean (EM) climatology that affected the severity and length of droughts/wet spells associated with multiyear episodes of Dead Sea level falls/rises and (b) determine that EM cyclone tracks were different in average number and latitude in wet and dry years in Jerusalem. The mean composite sea level pressure and 500-mb height anomalies indicate that the potential causes for wet and dry episodes span the entire EM and are rooted in the larger-scale northern hemisphere atmospheric circulation. We also identified remarkably close association (within radiocarbon resolution) between climatic changes in the Levant, reflected by level changes, and culture shifts in this region.
מידע נוסף

מאמרים ופרסומים אחרונים

מרכז הידע הישראלי להערכות לשינויי אקלים
2015

Periodic Report Summary 1 - DYNAMIC (DYNamic feedbacks of climate impacts on current Adaptation and Mitigation Investment Choice)

The DYNAMIC (DYNamic feedbacks of climate impacts on current Adaptation and Mitigation Investment Choice) project proposes a novel framework to evaluate the economic consequences of climate change impacts and related policy responses.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2015

בחינת תרומת קבוצות סוציו אקונומיות בישראל לפליטות גזי חממה מצריכת מזון ביתי

לייצור המזון, במיוחד בחקלאות התעשייתית, נודעת השפעה ממשית על היקף פליטות גזי חממה באופן ישיר או עקיף. גזי חממה אלו נוצרים בכל שלבי מחזור החיים של המזון, החל משלב החקלאות ותשומותיו, דרך הייצור, הפצה, קירור, קמעונאות, הכנת המזון בבית וכלה בסילוק הפסולת.למעשה, בעוד שבמחקרים השונים קיימת הסכמה על כך שפליטות גזי חממה מייצור המזון וצריכתו מהוות חלק משמעותי מפליטות גזי החממה בעולם, המחלוקת המחקרית נסובה סביב הערכת היקף הפליטות. לדוגמא, לפי דוח של האו"ם מ- 2014 14.5% מפליטות גזי החממה כתוצאה מפעילו
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2014

Explaining Extreme Weather Events of 2013 from a Climate Perspective

The annual Bulletin of the American Meteorological Society (BAMS) special issue on the attribution of last year’s extreme weather events is published today. This year’s issue “explaining extreme events of 2013 – from a climate perspective” includes two papers led by researchers from our climateprediction. This is a highly-cited and influential annual publication coined in 2012 asking whether and to what extent anthropogenic climate change altered the risk of major extreme weather events of the p
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2014

Lima call for climate action- Decision

Climate Action & UNEP delivered their fifth annual Sustainable Innovation Forum on December 9 in Lima. This year’s event brought together close to 500 leaders from key United Nations bodies, governments, international & regional companies and leading non-governmental organisations (NGO's).
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2012

Climate Prediction for Adaptation: Who needs what?

The role of short- and long-term climate predictions in determining the success of adaptation to climate change is investigated. A simple theoretical model that captures the relationship between adaptive performance, decision structure, and prediction accuracy at different temporal scales is developed, and its implications deduced. It is shown that users who face high adjustment costs (i.e. are inflexible) depend more heavily on accurate long-term predictions than those who are able to adjust
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2012

UK climate change risk assessment: government report

The Government published the UK Climate Change Risk Assessment (CCRA) on 25 January 2012, the first assessment of its kind for the UK and the first in a 5 year cycle. It sets out the main priorities for adaptation in the UK under 5 key themes identified in the CCRA 2012 Evidence Report - Agriculture and Forestry; Business, industries and Services; Health and Wellbeing; Natural Environment and Buildings and Infrastructure - and describes the policy context, and action already in place to tackle
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

2011 Bonn Declaration of Mayors

This declaration is the outcome document of the Mayors Adaptation Forum, which forms the Mayors segment of the Resilient Cities 2011 congress. It highlights the need to build resilience to disasters as a critical issue. It also signals the need to take appropriate action to build local capacities in reducing risk to disasters including those exacerbated by climate change.
The declaration advocates for the implementation of the following: (i) mainstreaming new adaptation and resilience standard
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

A double-resolution transient RCM climate change

A double-resolution regional experiment on hydrodynamic simulation of climate over the eastern Mediterranean (EM) region was performed using an International Center for Theoretical Physics, Trieste RegCM3 model. The RegCM3 was driven from the lateral boundaries by the data from the ECHAM5/MPI-OM global climate simulation performed at the MPI-M, Hamburg and based on the A1B IPCC scenario of greenhouse gases emission. Two simulation runs for the time period 1960-2060, employing spatial resolutions
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

Climate Change Adaptation and Real Option Evaluation: A Case Study in Campeche, Mexico

This report illustrates the application of a (relatively) new method to guide decision making under high (and unknowable) levels of uncertainty. The approach allows for the identification of robust policy options that are economically beneficial under different scenarios and varying levels uncertainty. Option value techniques are commonly employed in the finance literature to identify investment decisions that are resilient across a spectrum of outcomes. The methods are technically advanced
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

ipcc summary for policymakers

The Working Group III Special Report on Renewa
ble Energy Sources and Climate Change
Mitigation (SRREN) presents an assessment of th
e literature on the scientific, technological,
environmental, economic and social aspects of
the contribution of six renewable energy (RE)
sources to the mitigation of climate change. It is
intended to provide policy relevant information to
governments, intergovernmental processes and ot
her interested parties. This Summary for
Policymakers provides an ov
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2008

Climate change- vulnerability and adaptation indicators

The purpose of this Technical Paper is to rehearse some fundamental concepts surrounding the
development and delineation of adaptation indicators. It builds upon the outputs of an Expert meeting
on climate change vulnerability and adaptation indicators (Budapest, September 2008) and on the
contents of a Background Paper that was prepared for the meeting.
מידע נוסף
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