1 Temporal Trend in Anthropogenic Sulfur Aerosol Transport from Central and Eastern Europe to Israel Arnon Karnieli The Remote Sensing Laboratory Jacob Blaustein Institute for Desert Research Ben-Gurion University of the Negev

2 Aerosol Size Distribution Origin Chemical composition; Optical properties; Transport distance; Deposition rate; Transformation mechanisms. The two groups tend to differ in their:

3 Sulfur (S)

4 From Gas to Aerosol After combustion of the fossil fuels in the power plants, the sulfur dioxide is converted via a complex series of chemical reactions in the atmosphere to sulfuric acid and sulfate aerosols. Sulfur dioxide (SO 2 ) Sulfuric acid (H 2 SO 4 ) Sulfate (SO 4 2− ) The lifetime of sulfur in the atmosphere ranges from 12 hours to 6 days.

5 SO 2 in Europe Temporal trends of sulfur dioxide emissions in Europe (sources: Vestreng et al., 2008) 20 Tg 57 Tg

6 SO 2 Sources 1990 West EuropeEast EuropeFormer USSR Tg Tg29.05 Tg Source: EDGAR (

7 SO 2 Sources 2000 West EuropeEast EuropeFormer USSR Tg Tg14.56 Tg Source: EDGAR (

8 Trends by Countries Source: EDGAR ( % decline The most industrial countries

9 Hypothesis and Objectives Hypothesis The temporal trend of reduction in SO 2 emissions in central and eastern Europe after 1991 results in a similar trend in sulfate levels in Israel as a receptor site. Objective To verify the hypothesis using several independent long- term aerosol datasets.

10 Methodology This hypothesis was examined by five independent long-term analyses – Processing of satellite images; Aerosol optical thickness and relative aerosol size analyses; Calculations of the radiative forcing; Analysis of aerosol samples; Airmass backward trajectories analysis. The study was restricted to the summer season thus only dry sulfate particles are involved rather than the removal of sulfate from the atmosphere by wet deposition.

11 Source and Sink Areas Central & East Europe Sede Boker Campus Source Sink

12 Summer Synoptic Map High Low

13 MODIS-Derived AOT Aerosol Optical Thickness Fine mode fraction

14 Spaceborne Aerosol Optical Thickness (July – August)

15 AERONET AERONET Worldwide sites AERONET Sede Boker site

16 Ground Aerosol Optical Characteristics (August)

17 Global Radiative Forcing

18 Modeled Radiative Forcing

19 Aerosol sampler Sampling: “Gent” PM10 Staked Filter Unit (SFU): - Coarse fraction (2.5-10µm) - Fine fraction (< 2.5µm)

20 Ground Coarse Fraction Aerosols

21 Ground Fine Fraction Aerosols

22 Ground Sulfur Fine Fraction Aerosols

23 S Airmass Backward Trajectories 5-days Max 4,000 m 1995 – events Threshold S > 3 μg m -3

24 Conclusions (1) The study confirmed the hypothesis that the temporal trend of reduction in SO 2 emissions in central and eastern Europe after 1991 results in a similar trend in sulfate levels in Israel as a receptor site. This conclusion is based on several independent long-term aerosol datasets.

25 Israel Gg Gg447.7 Gg 60% increase between 1990 to 2000! Source: EDGAR (

26 Conclusion (2) Sede Boker site is not affected by aerosols originated in the Israeli coastal zone and can be served as a background station.

27 and special thanks to: Yevgeny Derimian, Rodica Indoitu, Natalya Panov, Robert C. Levy, Lorraine A. Remer, Willy Maenhaut and Brent N. Holben

28 Thanks

29 10 events < 500 m26 events < 1000 m 61 events < 2000 m87 events < 4000 m

30 Single Scattering Albedo (SSA) SAA is a measure of the amount of aerosol light extinction due to scattering Anthropogenic aerosolsMineral dust

31 Single Scattering Albedo (August)

32 Aerosol Size Distribution (24-26 Jan. 03)

33 Nes Ziona Single Scattering Albedo (Jan , 2004)

34 AOT trend

35 Sulfur trend

36 Synoptic map Mean June- September 1000 hPa height contours Source: Alpert et al. 1990

37 S back trajectories

38 Trends by regions Source: EDGAR (