HR: 0800h
AN: A11C-0615    [Abstracts]
TI: Distributions of Tropospheric SO2 from the INTEX field campaign
AU: * Kim, S
EM: skim@eas.gatech.edu
AF: School of Earth and Atmospheric Sciences, Georgia Tech, Atlanta, GA 30332, United States
AU: Huey, L G
AF: School of Earth and Atmospheric Sciences, Georgia Tech, Atlanta, GA 30332, United States
AU: Stickel, R E
AF: School of Earth and Atmospheric Sciences, Georgia Tech, Atlanta, GA 30332, United States
AU: Dibb, J E
AF: Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, United States
AU: Scheuer, E
AF: Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, United States
AU: Diskin, G
AF: NASA Langley Research Center, Langley Research Center, Hampton, VA 23681, United States
AU: Sachse, G W
AF: NASA Langley Research Center, Langley Research Center, Hampton, VA 23681, United States
AU: McNaughton, C S
AF: Department of Oceanography, University Hawaii, Honolulu, HI 96822, United States
AU: Clarke, A D
AF: Department of Oceanography, University Hawaii, Honolulu, HI 96822, United States
AB: SO2 was measured in the troposphere by chemical ionization mass spectrometry from the NASA DC-8 research aircraft during the Intercontinental Chemical Transport Experiment (INTEX). During the three phases of the INTEX field campaign, we sampled outflow from the eastern U.S., Mexico City, and Asia. In the eastern U.S. and its outflow region, significantly enhanced free tropospheric SO2 (tens - hundreds pptv) was observed from active deep convection and frontal uplift processes in the summer of 2004. Over the Gulf of Mexico in March, 2006, the median SO2 profile demonstrates very high SO2 (few ppbv) in the lower troposphere (0 – 4 km) and very low SO2 (mostly < 5 pptv) in the mid and upper troposphere (4 - 12km). Back trajectory analysis indicated that the high SO2 episodes in the lower troposphere have distinct origins such as Veracruz and the Yucatan Peninsula for the MBL and inland Mexico for altitudes above 1 km. In the eastern Pacific during spring 2006, enhanced SO2 layers (up to ~1 ppbv), transported from Asia were frequently found throughout the free troposphere especially in the latitude range 40-60 oN. A correlation analysis with aerosol parameters illustrates that upper tropospheric SO2, transported by deep convection shows a strong correlation with ultrafine aerosols. However, non volatile aerosols show a strong correlation with upper tropospheric SO2, transported by the frontal uplift process. This characteristic indicates that most high SO2 episodes, sampled over the eastern Pacific were transported by frontal uplift processes in Asia. However, those sampled over the eastern U.S. were transported by both deep convections and frontal uplift processes from the south eastern U.S. and the Ohio Valley.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting