מאמרים

מרכז הידע הישראלי להערכות לשינויי אקלים
2011

The spatio-temporal distribution of lightning over Israel and the neighboring area and its relation to regional synoptic systems

The spatio-temporal distribution of lightning flashes over Israel and the neighboring area and its relation to the regional synoptic systems has been studied, based on data obtained from the Israel Lightning Location System (ILLS) operated by the Israel Electric Corporation (IEC). The system detects cloud-to-ground lightning discharges in a range of ~500 km around central Israel (32.5° N, 35° E). The study period was defined for annual activity from August through July, for 5 seasons in the period 2004–2010. The spatial distribution of lightning flash density indicates the highest concentration over the Mediterranean Sea, attributed to the contribution of moisture as well as sensible and latent heat fluxes from the sea surface. Other centers of high density appear along the coastal plain, orographic barriers, especially in northern Israel, and downwind from the metropolitan area of Tel Aviv, Israel. The intra-annual distribution shows an absence of lightning during the summer months (JJA) due to the persistent subsidence over the region. The vast majority of lightning activity occurs during 7 months, October to April. Although over 65 % of the rainfall in Israel is obtained during the winter months (DJF), only 35 % of lightning flashes occur in these months. October is the richest month, with 40 % of total annual flashes. This is attributed both to tropical intrusions, i.e., Red Sea Troughs (RST), which are characterized by intense static instability and convection, and to Cyprus Lows (CLs) arriving from the west.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

Regional and local climatic effects on the Dead-Sea evaporation

The natural evaporation in the Dead-Sea is a very important meteorological parameter to the local industries at Sdom. It was found that the pan evaporation in Sdom has recently increased by 20–25%. In this paper we explore the reasons for this increase. It is found that both large-scale and local climatic changes have contributed to the evaporation increase in the Dead Sea Valley. The large-scale (global) change potentially associated with the global warming, resulted in changes of the frequencies of some synoptic systems in the region. The local change is a result of the recent Dead-Sea drying, which reduced the local Dead-Sea breeze while intensifying the Mediterranean-Sea breeze penetrating the Dead Sea Valley. It is suggested that while the local effect was the dominant climatic change factor in the Dead-Sea Valley in the 1970–1990, the global effect becomes the dominant one in the more recent evaporation increase in the Dead-Sea.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2010

Increasing trend of African dust, over 49 years, in the eastern Mediterranean

Dust observations in Israel were carried out since 1958. During 1958–2006, 966 dust days were observed. The dust days have been analyzed through their association with the regional eastern Mediterranean synoptic types, as classified by the Tel Aviv University method. Among the synoptic types, the most contributing were winter lows (with 368 days), Red Sea Troughs (214 days), and highs (211 dust days). Association of dust with highs is a new result, not found in the literature to date. Out of the total occurrences of Sharav lows, 36% are associated with dust, out of total winter lows 13%, with a winter low south to Cyprus having a 30% probability to produce a dust day, and of Red Sea Trough days 6% were associated with dust. Annual occurrence of dust days follows the changes in the occurrence of the regional synoptic systems: the number of dust days associated with Red Sea Troughs has increased by 2.3 d/10 yr, and with highs by 0.9 d/10 yr. The total incidence of dust days has increased with an average rate of 2.7 days per decade. This increasing trend in dust storm occurrence fits with previous results for the eastern Mediterranean and south Europe. Since dust storms are a regional phenomenon and reach south, central, and western Europe, this increase has implications for the entire Mediterranean and European regions. The results show potential for statistical forecasting of dust 1 day in advance. Such forecasts are important for public health warnings and for air transportation.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2007

Suspended dust over southeastern Mediterranean and its relation to atmospheric circulations

The Middle East deserts are often subjected to dust, which reduces horizontal visibility to 5 km, and sometimes even to < 1 km. The present study examines the annual and inter-annual occurrences of dust events based on 37 years of visibility observations from Hazerim (near Beer Sheba) correlated with PM10 dust concentration. The visibility data was converted to PM10 dust concentration, using concurrent data for three years. We then analyse the linkage between dust and synoptic- to global-scale weather systems. The monthly data indicate that the dust season starts in October and ends in May, with a maximum in March. More than 89% of the total annual dust is accumulated between December and May, the ‘high dust season’. The annual totals vary as much as an order of magnitude from year to year. The synoptic system that produces the majority of the dust over the northern Negev is the Cyprus Low, contributing 2/3 of both the total yearly dust yield and of the number of dust observations. This suggests that a positive relationship exists between the dust in the Negev and rainfall in north Israel, both of which are generated by Cyprus Lows. Indeed, a significant (at 0.05 level) correlation of + 0.30 was found between the two. Correlation maps evidence that in dust-rich years the cyclonic activity over the Mediterranean is abnormally high and in poor-dust years it is low. A highly significant negative correlation (−0.66) was found between the dust yield and the intensity of the North Atlantic oscillation (NAO), which modulates the cyclonic activity over Europe and the northern Mediterranean. This may also imply that periods in which more dust accumulated as loess in the northern Negev may indicate the existence of negative NAO phase, and concurrently, warmer conditions over the Sahara, colder conditions over Europe and enhanced rainfall over the Mediterranean Basin. Copyright © 2007 Royal Meteorological Society
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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