HR: 1340h
AN: GC23A-1294    [Abstracts]
TI: In Situ Measurements of Aerosol Mass Concentration and Spectral Absorption in Xianghe, SE of Beijing, China
AU: * Chaudhry, Z
EM: zahra@atmos.umd.edu
AF: Department of Atmospheric and Oceanic Science, University of Maryland, 3417 Computer and Space Sciences Building, College Park, MD 20742 United States
AU: Martins, V
EM: martins@climate.gsfc.nasa.gov
AF: JCET/UMBC, NASA/GSFC 613.2, Greenbelt, MD 20771 United States
AU: Li, Z
EM: zli@atmos.umd.edu
AF: Department of Atmospheric and Oceanic Science, University of Maryland, 3417 Computer and Space Sciences Building, College Park, MD 20742 United States
AB: China's rapid industrialization over the last few decades has affected air quality in many regions of China, and even the regional climate. As a part of the EAST-AIRE (East Asian Study of Tropospheric Aerosols: an International Regional Experiment) study, Nuclepore filters were collected in two size ranges (PM10 and PM2.5) at 12 hour intervals since January 2005 at Xianghe, about 70 km southeast of Beijing. Each filter was analyzed for mass concentration, aerosol scattering and absorption efficiencies. Mass concentrations during the winter months (January-March) ranged from 9 to 459 μg/m³ in the coarse mode with an average concentration of 122 μg/m³, and from 11 to 203 μg/m³ in the fine mode with an average concentration of 45 μg/m³. While some of the extreme values are likely linked to local emissions, regional air pollution episodes also played important roles. Absorption efficiency measurements at 550 nm show very high values compared to measurements performed in the United States during the CLAMS experiment. The spectral mass absorption efficiency was measured from 350 to 2500 nm and shows large differences between the absorption properties of soil dust, black carbon, and organic aerosols. The strong spectral differences observed can be related to differences in refractive indices from the several collected species and particle size effects. The absorption properties from aerosols measured in China show large absorption efficiencies, compared to aerosols measured in the US, possibly linked to different technology practices used in these countries. For organic plus black carbon aerosols, where the refractive index seems to be relatively constant, the absorption efficiency spectral dependence for fine mode aerosols falls between 1/λ and 1/λ². The coarse mode absorption shows much less spectral dependence.
DE: 1610 Atmosphere (0315, 0325)
DE: 1637 Regional climate change
SC: Global Climate Change [GC]
MN: Fall Meeting 2005