GEOC 161 |
| Vicki H. Grassian, Department of Chemistry, Department of Chemistry, University of Iowa, Iowa City, IA 52242 |
| Mineral dust aerosol makes up a large fraction of the tropospheric aerosol mass. This is significant because mineral dust aerosol can impact climate, biogeochemical cycles, human health and atmospheric chemistry. The focus of this talk is on the heterogeneous chemistry of carbonate containing mineral dust aerosol with several trace atmospheric gases including nitric acid, sulfur dioxide and acetic acid. These reactions are done under ambient conditions of temperature, pressure and relative humidity. Several experimental methods have been used to probe reactions at the calcite-air interface. These include transmission and ATR FT-IR spectroscopy, atomic force microscopy and scanning electron microscopy coupled with energy dispersive x-ray analysis. The results of our laboratory study can be used to explain data collected during two field campaigns (TRACE-P and ACE-Asia) that were conducted in spring ‘01. During these field campaigns, a large dust storm occurred and several reactions on mineral dust aerosol, in particular the carbonate component of the aerosol, were observed. Mechanisms of these reactions in the atmosphere can be deduced from the laboratory studies.
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Interfacial Phenomena: Linking Atomistic and Macroscopic Properties
1:20 PM-5:40 PM, Wednesday, March 31, 2004 Marriott -- Marquis NW, Oral
Division of Geochemistry |