מאמרים

מרכז הידע הישראלי להערכות לשינויי אקלים
2011

PM10 composition during an intense Saharan dust transport event over Athens (Greece)

The influence of Saharan dust on the air quality of Southern European big cities became a priority during the last decade. The present study reports results on PM10 monitored at an urban site at 14 m above ground level during an intense Saharan dust transport event. The elemental composition was determined by Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF) for 12 elements: Si, Al, Fe, K, Ca, Mg, Ti, S, Ni, Cu, Zn and Mn. PM10 concentrations exceeded the EU limit (50 μg/m3) several times during the sampling period. Simultaneous maxima have been observed for the elements of crustal origin. The concentrations of all the elements presented a common maximum, corresponding to the date where the atmosphere was heavily charged with particulate matter permanently for an interval of about 10 h. Sulfur and heavy metal concentrations were also associated to local emissions. Mineral dust represented the largest fraction of PM10 reaching 79%. Seven days back trajectories have shown that the air masses arriving over Athens, originated from Western Sahara. Scanning Electron Microscopy coupled with Energy Dispersive X-ray analysis (SEM-EDX) revealed that particle agglomerates were abundant, most of them having sizes < 2 μm. Aluminosilicates were predominant in dust particles also rich in calcium which was distributed between calcite, dolomite, gypsum and Ca–Si particles. These results were consistent with the origin of the dust particles and the elemental composition results. Sulfur and heavy metals were associated to very fine particles < 1 μm.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2010

Numerical simulation of a continental‐scale Saharan dust event

Using an integrated dust-storm modeling system, we simulate the severe Saharan dust episode between 1 and 10 March 2004. The simulations are compared with surface synoptic data and satellite images and are found to agree well with the observations. The synoptic systems that generated the dust storms and the evolution of the dust patterns are analyzed. It is revealed that a cyclogenesis over central Sahara, accompanied by an anticyclone over the Atlantic and a monsoon trough in the tropics, was responsible for the widespread continental-scale dust storms in North Africa. Dust first appeared in west Sahara, then in east Sahara and much of the dust emitted from east Sahara was transported to the monsoon trough, resulting in high concentrations of suspended dust over the Sahel (column dust load up to 10 g m−2). The main dust source regions were (1) Mauritania, (2) Chad and Niger, and (3) Libya, Egypt, and Sudan. The region between 10°N and 17°N was one of net dust deposition. We estimate that 715.8 megatons (Mt) of dust was emitted from North Africa during the episode, 608.2 Mt of which was deposited to the continent, and the net dust emission was 107.6 Mt. Of the 107.6 Mt, with respect to the model domain, 7.3 Mt was deposited to the ocean, 79.8 Mt was transported across the domain boundaries, and 20.5 Mt was suspended in the atmosphere.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2010

Quantification of Saharan dust contribution to PM10 concentrations over Italy during 2003-2005

Italy is frequently affected by Saharan dust intrusions, which result in high PM10 concentrations in the atmosphere and can cause the exceedances of the PM10 daily limits (50 μg m−3) set by the European Union (EU/2008/50). The estimate of African dust contribution to PM10 concentrations is therefore a key issue in air quality assessment and policy formulation. This study presents a first identification of Saharan dust outbreaks as well as an estimate of the African dust contribution to PM10 concentrations during the period 2003–2005 over Italy. The identification of dust events has been carried out by looking at different sources of information such as monitoring network observations, satellite images, ground measurements of aerosol optical properties, dust model simulations and air mass backward trajectory analysis. The contribution of Saharan dust to PM10 monthly concentrations has been estimated at seven Italian locations. The results are both spatially (with station) and temporally (with month and year) variable, as a consequence of the variability of the meteorological conditions. However, excluding the contribution of severe dust events (21st February 2004, 25th–28th September 2003, 23rd–27th March 2005), the monthly contribution of dust varies approximately between 1 μg m−3 and 10 μg m−3 throughout year 2005 and between 1 μg m−3 and 8 μg m−3 throughout year 2003. In 2004 the dust concentration is lower than 2003 and 2005 (<5 μg m−3 at all sites). The reduction in the number of daily exceedances of the limit value (50 μg m−3) after subtraction of the dust contribution is also calculated at each station: it varies with station between 20% and 50% in 2005 and between 5% and 25% in 2003 and 2004.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2004

Vertical distribution of Saharan dust based on 2.5-year model predictions

Within the framework of the NASA-Israeli MEIDEX project, the averaged 3D-distribution of Saharan dust was estimated and analyzed. This averaged distribution was based on the 2.5-year database of 48-h dust forecasts produced by the dust prediction system, which had been developed earlier at the University of Athens and subsequently modified in Tel Aviv University. The performed climatological analysis is the first one based on a large archive of dust distribution over the whole Sahara and vicinity regions; the total amount of vertical profiles in this archive is approximately 107 per year. Vertical distributions of dust reflect differences between the Atlantic and the Mediterranean dust transport. As a whole, the Mediterranean dust is found to be within a wider range of altitudes, penetrating rather higher into the troposphere. On average, dust over the Atlantic penetrates up to ≤5 km while over the Mediterranean up to ≤8 km. The characteristic feature of dust vertical profiles over the main Saharan dust source near Lake Chad is its maximal concentration near the surface. From April to June averaged profiles over the Chad basin in the Sahara are restricted below the level of ∼4.5 km. In the winter months and in March, dust concentration over the Chad basin is closer to the surface, under 1.5 km. Dust also maximizes near the surface over another dust source, which is the major one in summer, located in West Africa. These results are consistent with dust-layer altitude ranges from present-day lidar soundings. Besides, the results are in accordance with general synoptic knowledge of the mechanism of dust transport to the Mediterranean. However, only quantitative comparisons of model vertical profiles against lidar measurements, which are under way now, can validate the forecast vertical distribution of Saharan dust.
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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