HR: 0800h
AN: A51E-0836    [Abstracts]
TI: Evaluating the Contribution of Carbonaceous Aerosols to CCN with a Global Aerosol Microphysics Model
AU: * Adams, P J
EM: petera@andrew.cmu.edu
AF: Carnegie Mellon University, Civil and Environmental Engineering 5000 Forbes Ave, Pittsburgh, PA 15213 United States
AU: Chen, K
EM: kaipingc@andrew.cmu.edu
AF: Carnegie Mellon University, Civil and Environmental Engineering 5000 Forbes Ave, Pittsburgh, PA 15213 United States
AB: A two-moment sectional model of aerosol microphysics is included in the GISS GCM in order predict tropospheric cloud condensation nuclei (CCN) concentrations. The model includes sulfate, sea-salt, elemental carbon, organic carbon, and mineral dust aerosols. The aerosol size distribution is simulated explicitly by modeling the rates of nucleation, condensation, and coagulation. Here we use the model to examine the contribution of carbonaceous aerosols to tropospheric CCN levels. Using currently available emissions estimates, the model predicts that primary organic carbon (OC) aerosols make a dominating contribution. This contribution includes the effect of ultrafine primary OC particles that must grow to CCN sizes as well as OC particles that are already large enough when emitted. The sensitivity of CCN levels to uncertainties in our knowledge of aging will be discussed.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting