title: Application of the SO4(2-)/Se tracer technique to study SO2 oxidation in cloud and fog on a time scale of minutes.
abstract: We have demonstrated the use of Se as a tracer to quantitatively determine in situ SO4(2-) production from SO2 oxidation in clouds and fogs. Until now, it has not been possible to study the kinetics of SO2 oxidation because the aerosol sampling interval for Se determination was limited to 2 h or longer. Here we report results of 5-min aerosol measurements carried out at Lahore, Pakistan, during January 9-11, 2001, using new methodology for Se analysis coupled with hydride generation and ICP-MS detection. These improvements will enable the tracer technique to determine in situ SO4(2-) production in clouds and fogs on a time scale of several minutes and possibly 1 min. The method may prove useful for kinetic studies of in-cloud SO2 oxidation and in the study of other phenomena such as atmospheric mixing, cloud drop lifetimes, and aerosol formation that occur on the time scale of a few minutes.
authors.affiliation: Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, New York 12201-0509, USA. lhusain@wadsworth.org
authors.forename: Liaquat
authors.initials: L
authors.lastname: Husain
authors.forename: Badar
authors.initials: B
authors.lastname: Ghauri
authors.forename: Karl
authors.initials: K
authors.lastname: Yang
authors.forename: Adil R
authors.initials: AR
authors.lastname: Khan
authors.forename: O V
authors.initials: OV
authors.lastname: Rattigan
mesh_terms: D001272:Atmosphere / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D005374:Filtration; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010154:Pakistan; D012643:Selenium / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000737:chemistry*; D013997:Time Factors
chemical_list: D013458:Sulfur Dioxide; D012643:Selenium