AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Characterization of Aral Sea Particulate Matter in Kyrgyzstan
NITIKA DEWAN, Brian Majestic, Martin Shafer, James Schauer, Paul A. Solomon, University of Denver
Abstract Number: 365 Working Group: Source Apportionment
Abstract The Aral Sea has receded up to 90% in size. As a result, these sediments are resuspended by the wind and may be a new source of particulate matter (PM) in Central Asia, which could have an impact on human health and climate. In this study, Sr isotopes, along with other elemental compositions, are used as tracers to explore if the Aral Sea sediments are an important source of air pollution to Central Asia. A series of PM$_(2.5) and PM$_(10) resuspended sediments and atmospheric PM samples were collected at two urban sites (Bishkek and Lidar) in Kyrgyzstan, located ~1,500 km downwind of the Aral Sea. The average $^(87)Sr/$^(86)Sr ratio for the Aral Sea sediments was found to be 0.70987 (0.70947-0.71064), indicating that exposed sediments are primarily influenced by quickly eroding rocks at high elevations. The ratio in the surface soils in Kyrgyzstan is dominated by the weathering of native rocks and vegetation showing an average $^(87)Sr/$^(86)Sr ratio of 0.71579 (0.71448-0.71739). $^(87)Sr/$^(86)Sr of PM$_(10) samples (0.70951-0.71387) are slightly more radiogenic than those in the PM$_(2.5) samples (0.70947-0.71274). The airborne PM collected in Kyrgyzstan has an average $^(87)Sr/$^(86)Sr ratio of 0.71177 (0.70948-0.71335), which is in between the two end members, indicating a mixture of Aral Sea sediments and local soils.