Impact of aerosol and clouds on 3D irradiance fields during the GoMACCS experiment

HR: 17:45h
AN: A34A-08 [Abstracts]
TI: Impact of aerosol and clouds on 3D irradiance fields during the GoMACCS experiment
AU: * Schmidt, S
EM: sebastian.schmidt@lasp.colorado.edu
AF: University of Colorado, LASP Campus Box 392, Boulder, CO 80309-0392,
AU: Feingold, G
EM: graham.feingold@noaa.gov
AF: NOAA, Earth System Research Laboratory 325 Broadway, Boulder, CO 80305,
AU: Pilewskie, P
EM: peter.pilewskie@lasp.colorado.edu
AF: University of Colorado, LASP Campus Box 392, Boulder, CO 80309-0392,
AU: Jiang, H
EM: Hongli.Jiang@noaa.gov
AF: NOAA, Earth System Research Laboratory 325 Broadway, Boulder, CO 80305,
AB: The GoMACCS field experiment in the heavily polluted industrial Houston area was specifically designed to study the microphysical and macrophysical transformations that clouds may undergo when influenced by aerosol. Solar spectral irradiance is dependent not only on the optical properties of clouds and aerosol but also on their spatial distribution as well as the surface albedo. A radiative signature from aerosol can only be found by clearly separating 3D, surface, and aerosol effects. To this end, we simulated fields of convective clouds based on soundings in the Houston area using a large eddy simulation (LES) with size-resolved microphysics. We then modeled the irradiance fields associated with these clouds using the 3D drop effective radius and water content and 3D aerosol properties as input, and compared with the measured data from an airborne Solar Spectral Flux Radiometer (SSFR). This constitutes a rigorous test of the ability of the LES to simulate the radiative response of clouds to perturbations by aerosol. We discuss the extent to which the irradiance field associated with the LES cloud simulations compares to the observed irradiance field and its spatial and temporal variability, as well as combined aerosol, cloud and 3D effects.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0321 Cloud/radiation interaction
DE: 0360 Radiation: transmission and scattering
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting