Convective lofting links Indian Ocean air pollution to paradoxical South Atlantic ozone maxima

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View full article: HTML; PDF GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L06103, doi:10.1029/2003GL018866, 2004 Convective lofting links Indian Ocean air pollution to paradoxical South Atlantic ozone maxima R. B. Chatfield NASA Ames Research Center, USA H. Guan NASA Ames Research Center, USA BAER Inst., USA A. M. Thompson NASA Goddard Research Center, USA J. C. Witte NASA Goddard Research Center, USA SSAI, USA Abstract [1] We describe a broad resolution of the “Atlantic Parado” concerning the seasonal and geographic distribution of tropical tropospheric ozone. We highlight periods of significant maximum tropospheric O₃ for Jan.–April, 1999, exploiting satellite estimates and SHADOZ (Southern Hemisphere Additional Ozonesondes). Trajectory analyses connecting sondes and Total Tropospheric Ozone (TTO) maps suggest a complex influence from the Indian Ocean: beginning with mixed combustion sources, then low level transport, cumulonimbus venting, possible stratospheric input, and finally high-level transport to the west, with possible mixing over Africa. For the Jan.–March highest column-O₃ periods in the Atlantic, distinct sounding peaks trace to specific NO sources, especially lightning, while in the same episodes, recurring every 20–50 days, more diffuse buildups of Indian-to-Atlantic pollution make important contributions. Received 17 October 2003; revised 3 December 2003; accepted 4 February 2004; published 16 March 2004. Index Terms: 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; 3374 Meteorology and Atmospheric Dynamics: Tropical meteorology; 9340 Information Related to Geographic Region: Indian Ocean. View full article: HTML; PDF Citation: Chatfield, R. B., H. Guan, A. M. Thompson, J. C. Witte (2004), Convective lofting links Indian Ocean air pollution to paradoxical South Atlantic ozone maxima, Geophys. Res. Lett., 31, L06103, doi:10.1029/2003GL018866. Copyright 2004 by the American Geophysical Union.