HR: 1340h
AN: A23C-0812    [Abstracts]
TI: Use of Data Assimilation to Estimate the Aerosol Radiative Forcing
AU: Houben, H
EM: houben@humbabe.arc.nasa.gov
AF: Bay Area Environmental Research Institute, 560 Third Street West, Sonoma, CA 95476
AU: * Bergstrom, R W
AF: Bay Area Environmental Research Institute, 560 Third Street West, Sonoma, CA 95476
AU: Guan, H
AF: Bay Area Environmental Research Institute, 560 Third Street West, Sonoma, CA 95476
AU: Russell, P B
AF: NASA-Ames Research Center, MS 245-5, Moffett Field, CA 94035
AU: Chatfield, R
AF: NASA-Ames Research Center, MS 245-5, Moffett Field, CA 94035
AB: One of the major difficulties in assessing the aerosol radiative forcing is the interpretation and evaluation of a wide variety of satellite, aircraft, and surface measurements. In addition, the poor current state of knowledge of the global aerosol sources, sinks, and radiative properties makes relying on global climate models problematic. We are using data assimilation techniques to include measurements of atmospheric aerosols from many platforms in a global model, to improve the model simulations of the aerosol transport, and to assess the aerosol radiative forcing. We initially concentrate on the ACE-Asia and SAFARI 2000 campaigns for which there is much data, using the NCAR Community Atmosphere Model (CAM) to simulate the aerosol spatial distribution. Since radiances are the observables must closely related to our scientific goal of determining radiative forcing, we assimilate satellite-observed radiances directly---instead of the higher level data products that require assumptions about the aerosols and gases which may differ from instrument to instrument---using an adjoint of the radiative transport equation. (This technique has been successfully employed to assimilate data from the Mars Global Surveyor satellite.) We are also working on an adjoint of CAM that will allow full four-dimensional assimilation, with the prospect of improved determination of aerosol sources and sinks. With these tools, the assimilation of global satellite data can contribute to our knowledge of aerosol and tracer distributions, and particularly of aerosol radiative forcing.
DE: 3337 Numerical modeling and data assimilation
DE: 1610 Atmosphere (0315, 0325)
DE: 1640 Remote sensing
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting