Regional Transport of Atmospheric Aerosol in Central Asia: Characteristics and Provenance of Dust Events Observed in the Kyrgyz Republic

MARTIN SHAFER (1), James Schauer (1), Justin Miller-Schulze (1), Paul Solomon (2), Boris Chen (3), Sanjar Imashev (3), Maria Artamonova (4), Greg Carmichael (5)

(1) University of Wisconsin-Madison, Madison, (2) U.S. EPA ORD, Las Vegas, (3) Kyrgyz-Russian Slavic University, Bishkek, Kyrgyz Republic, (4) Institute of Atmospheric Physics, Moscow, Russia, (5) University of Iowa, Iowa City

     Abstract Number: 195
     Last modified: April 28, 2010

Abstract
To advance our understanding of regional and long-range transport of aerosol particulate matter (PM) in Asia we are characterizing sources of PM from Central Asia. A particular focus of our effort is on PM sourced from the Aral Sea region, the third largest source of mineral dust in Asia. We established two monitoring stations in the Kyrgyz Republic, where PM10 and PM2.5 samples were collected every other day from July 2008 through July 2009 for detailed chemical analysis. Measurements at both sites included 24-hr integrated filter-based samples for fine mass, OC/EC, ions, and 50+ elements by SF-ICPMS. Soil samples were obtained from the vicinity of the aerosol monitoring sites and from 10 locations surrounding the Aral Sea. Stable isotope ratios of Nd, Pb, and Sr were determined by MC-ICPMS in the soil samples as well as in composites of the aerosol PM.

With the detailed elemental and isotopic fingerprinting, we are determining: (a) if the chemistry of PM from event periods is substantially different from that of non-event periods; (b) whether the chemistry of the Aral Sea and Kyrgyz soils are distinguishable from those of western and central China; and (c) if we can define the contribution of Aral Sea region soils to aerosol PM in the Kyrgyz Republic Our event assessment is focused on a series of multi-day dust events, occurring primarily in spring and summer, that were captured during the year-long aerosol sampling program. In the first comprehensive elemental characterization of resuspendable soils from the Aral Sea region we show that the elemental composition of the soils are remarkably uniform thereby supporting chemical source apportionment models that treat this region as a relatively homogeneous source. Data also indicate that while the major element chemistry and Pb-isotope distribution of the Aral Sea and China soils are similar, the trace element fingerprints are significantly disparate, and potentially distinguishable in the context of aerosol PM source attribution.