HR: 0800h
AN: A11A-0026    [Abstracts]
TI: Climate Impact of Carbonaceous and Sulfate Aerosols in an Interactive Size-Resolving Aerosol-Climate Model
AU: * Kim, D
EM: dckim@mit.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MV 02139, United States
AU: Wang, C
EM: wangc@mit.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MV 02139, United States
AU: Ekman, A M
EM: annica@misu.su.se
AF: Stockholm University, Arrhenius Laboratory, Stockholm, SE-10691, Sweden
AU: Barth, M C
EM: barthm@ucar.edu
AF: National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, CO 80307, United States
AU: Rasch, P J
EM: pjr@ucar.edu
AF: National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, CO 80307, United States
AB: A multi-mode, two-moment aerosol model has been incorporated in the NCAR CAM3.0 to study the impact of anthropogenic aerosols on the global climate system. Seven aerosol modes, namely three sulfate, one external black carbon, one primary organic carbon, one sulfate/black carbon mixed mode and one sulfate/organic carbon mixed mode, are included in the model. Each aerosol mode predicts both number and mass concentration and thus aerosol size distribution which is critical to aerosol microphysics and optical property. When aerosols are assumed to be internally mixed, their chemical and optical properties are different than when they are externally mixed. Model results suggest that the major portions of black carbon and sulfate masses exist as mixed aerosols while two thirds of organic carbon mass is also in mixed form. In this study, multiple 60-year long simulations are carried out to examine the impact of the carbonaceous and sulfate aerosols in the climate system. Strong positive atmospheric forcing and negative surface forcing by the mixed aerosols affect the atmospheric thermal structure and consequently alter values of important parameters including cloud cover, height of planetary boundary layer, surface heat fluxes, and precipitation. The detailed results will be presented and discussed.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0365 Troposphere: composition and chemistry
DE: 1626 Global climate models (3337, 4928)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting