HR: 1330h
AN: A22B-1060    [PDF]
TI: Convective Lofting Links Indian Ocean Air Pollution to Recurrent South Atlantic Ozone Maxima
AU: * Chatfield, R B
EM: chatfield@clio.arc.nasa.gov
AF: NASA/Ames RC, MS 245-5, Moffett Field, CA 94035 United States
AU: Guan, H
EM: guan@clio.arc.nasa.gov
AF: NASA/Ames RC and BAER Institute, MS 245-5, Moffett Field, CA 94035 United States
AU: Thompson, A M
EM: thompson@gator1.gsfc.nasa.gov
AF: NASA/Goddard SFC, MS 916.0, Greenbelt, MD 20771 United States
AU: Witte, J
EM: witte@gavial.gsfc.nasa.gov
AF: NASA/Goddard SFC and SSA Inc, MS 916.0, Greenbelt, MD 20771 United States
AB: We extend on our analysis of equatorial tropospheric ozone to illustrate the contributions of South Asian pollution export in forming episodes of high O$_3$ over the Atlantic Ocean. We amplify on an earlier description of a broad resolution of the "Atlantic Paradox," for the Jan-Feb-March period, which included initial indications of a very long-distance contribution from South Asia. The approach has been to describe typical periods of significant maximum and minimum tropospheric ozone for early 1999, exploiting TOMS tropospheric ozone estimates jointly with characteristic features of the SHADOZ (Southern Hemisphere Additional Ozonesondes) ozone soundings. Further investigation of the Total Tropospheric Ozone (TTO) record for all of 1999 suggests that there are repeated periods of very long-distance Asian influence crossing Africa, with an apparent effect on those portions of the Atlantic Equatorial troposphere which are downwind. Trajectory analyses suggest that the pattern over the Indian Ocean is complex: a sequence invoving multiple or mixed combustion sources, low level transport, cumulonimbus venting, and high-level transport to the west seem to be indicated by the TTO record. Biomass burning, fossil and biofuel combustion, and lighting seem to all contribute. For the Atlantic, burning and lighting on adjacent continents as well as episodes of this cross-Africa long-distance transport are all linked in a coordinated seasonal march: all are related by movement of the sun. However, interseasonal tropical variability related to the Madden-Julian oscillation allows intermittent ozone buildups that depart from the seasonal norm.
DE: 0345 Pollution--urban and regional (0305)
DE: 0360 Transmission and scattering of radiation
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting