HR: 0800h
AN: A31C-0078    [Abstracts]
TI: A study of dust radiative forcing based on detailed transport and radiation models
AU: Luo, C
EM: chaoluo@icess.ucsb.edu
AF: University of California, Santa Barbara, Ellison Hall University of California, Santa Barbara, Santa Barbara, CA 93106 United States
AU: * Ricchiazzi, P
EM: paul@icess.ucsb.edu
AF: University of California, Santa Barbara, Ellison Hall University of California, Santa Barbara, Santa Barbara, CA 93106 United States
AU: Mahowald, N
AF: National Center for Atmospheric Research , P.O. Box 3000 Boulder, Colorado, USA 80307-3000 , Boulder, CO 80307 United States AB: Computational results for global radiative forcing due to mineral aerosols is presented. The average dust loading for the Winter, Spring, Summer and Fall seasons are computed by the MATCH transport model using currently active source regions. The MATCH model uses wet and dry deposition as loss mechanisms for four different size bins of aerosols transported by the model. MATCH provides vertically resolved profiles of water vapor, temperature, and dust density over the surface grid with 200km resolution. The diurnally-average dust radiative forcing is computed for each season using the SBDART radiative transfer model at a spectral resolution of 20 cm-1. The radiative properties of the dust are computed assuming spherical particles and a globally uniform size distribution. Both the shortwave and longwave calculation include the effects of radiation scattering. Within each column of the computational grid the surface reflection and emissivity spectral properties are computed as mixtures of 7 discrete surface types. The impact of non-Lambertian reflectance from the wind-roughened ocean surface is analyzed. In the thermal infrared, the effective ocean surface emissivity is shown to depend on precipitable water vapor and cloud cover, but does not strongly depend on the dust optical depth.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0360 Transmission and scattering of radiation
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting