HR: 08:30h
AN: A31B-03    [PDF]
TI: Radiative Forcing Associated with Changes in Upper Tropospheric Ozone Resulting from Deep Convection
AU: * Pickering, K E
EM: pickerin@atmos.umd.edu
AF: University of Maryland, Department of Meteorology, College Park, MD 20742 United States
AU: Mott, G
EM: gregm@atmos.umd.edu
AF: University of Maryland, Department of Meteorology, College Park, MD 20742 United States
AU: Stenchikov, G L
EM: gera@envsci.rutgers.edu
AF: Rutgers University, Department of Environmental Sciences, New Brunswick, NJ 08901 United States
AU: Park, R
EM: rpark@fas.harvard.edu
AF: Harvard University, Div. of Engineering and Applied Science, Cambridge, MA 02138 United States
AB: Deep convection transports large quantities of ozone precursors from the boundary layer to the upper troposphere. Once in the upper troposphere, ozone is produced efficiently and can be transported large distances. The 3-D University of Maryland Chemical Transport Model (UMD-CTM), driven by meteorological data from the NASA GEOS-3 Data Assimilation System, was run for the month of June 1985, encompassing a portion of the Kansas/Oklahoma PRESTORM experiment. In addition, the UMD-CTM was run for several 3 to 4 day periods during the same month but without convective transport. Upper tropospheric ozone downwind of major Central U.S. convective episodes was enhanced by as much as 20 ppbv in the model run with convection over the run without convection. Plumes of convectively enhanced ozone were noted exiting the east coast of the U.S. The radiation code from the GEOS-3 GCM was used to compute longwave and shortwave radiative fluxes at all model levels over a domain that included the U.S. and Western Atlantic. The radiative forcing associated with this increased upper tropospheric ozone was computed by subtracting the fluxes calculated using the ozone field from the CTM run without convection from the one run with convection. The results illustrate the importance of parameterizing convective transport properly in regional and global models.
DE: 0345 Pollution--urban and regional (0305)
DE: 0355 Thermosphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
DE: 3314 Convective processes
DE: 3359 Radiative processes
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting