HR: 14:10h
AN: A43G-02    [Abstracts]
TI: Impact of East Asian Summer Monsoon on Seasonal Variations of Aerosols over Eastern China
AU: * Zhang, L
EM: zhangli@mail.iap.ac.cn
AF: Institue of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
AU: * Zhang, L
EM: zhangli@mail.iap.ac.cn
AF: Graduate University, Chinese Academy of Sciences, Beijing, 100049, China
AU: Liao, H
EM: hongliao@mail.iap.ac.cn
AF: Institue of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
AU: Li, J
EM: ljp@lasg.iap.ac.cn
AF: Institue of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
AB: Ground measurements show that seasonal variations of aerosols in Eastern China are different from those in the Eastern United States; while aerosol concentrations are the highest in winter over Eastern China, they are the highest in summer in the Eastern United States. We apply a global 3-D chemical transport model (GEOS-CHEM) driven by NASA/GEOS assimilated meteorological data to quantify the roles of East Asian summer monsoon and seasonal variations of emissions of aerosols/aerosol precursors in influencing seasonal variations of sulfate, nitrate, ammonium, black carbon, and organic carbon aerosols in Eastern China. Model results show that East Asian summer monsoon plays a major role in determining seasonal variations of aerosols in Eastern China. Rainfall associated with summer monsoon leads to large wet deposition of aerosols, and the cross-equatorial flows from the Southern Hemisphere bring clean and wet air to Eastern China, all contributing to the low concentrations of aerosols in summer. Sensitivity studies with no seasonal variations in emissions indicate that East Asian summer monsoon can reduce aerosol concentration averaged over the domain of 110-120E and 20- 45N by 60-70%, as the averaged surface-layer aerosol concentration in July is compared with that in January. We also examine the influence of East Asian monsoon on transport and distributions of aerosols in the free troposphere. Results have important implications for air quality and climate effects of aerosols in Eastern China.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting