HR: 1340h
AN: C33B-1126    [Abstracts]
TI: Increases to cloud emissivity and downwelling surface thermal fluxes in the Arctic due to pollution from mid-latitudes
AU: * Garrett, T J
EM: tgarrett@met.utah.edu
AF: Department of Meteorology University of Utah, 135 S 1460 E Rm 819, Salt Lake City, Ut 84112 United States
AU: Zhao, C
EM: czhao@met.utah.edu
AF: Department of Meteorology University of Utah, 135 S 1460 E Rm 819, Salt Lake City, Ut 84112 United States
AB: A component of anthropogenic climate change is the potential effect of pollution aerosol on reflection of solar radiation by water clouds. Aerosol indirectly reduces solar radiative fluxes at the surface because it is hypothesized that greater activation of cloud droplets increases cloud scattering cross-sections. The Arctic is characterized by high concentrations of pollution from mid-latitudes in winter and spring, at a time when water clouds are widespread. However, any influence of elevated aerosol concentrations on cloud reflection is limited by low insolation of an already bright surface. Instead, the surface is most affected by an influence of pollution increases cloudy absorption of terrestrial radiation. From four years of ground based measurements obtained from the Climate Monitoring Diagnostics Laboratory, and the Atmospheric Radiation Measurement sites near Barrow, Alaska, we show that pollution aerosol indirectly increase Arctic cloud thermal emissivity by up to 0.07, and insulation of the Arctic cryosphere by up to 4 W m^-2.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0321 Cloud/radiation interaction
DE: 0750 Sea ice (4540)
SC: Cryosphere [C]
MN: Fall Meeting 2005