HR: 11:50h
AN: A22B-07    [Abstracts]
TI: Observations of Cloud Reflectance and Aerosol Optical Depths over India and the Indian Ocean
AU: * Massie, S
EM: massie@ucar.edu
AF: Steven T Massie, NCAR PO Box 3000, Boulder, CO 80307 United States
AU: Heymsfield, A
EM: heyms1@ucar.edu
AF: Steven T Massie, NCAR PO Box 3000, Boulder, CO 80307 United States
AU: Schmitt, C
EM: schmittc@ucar.edu
AF: Steven T Massie, NCAR PO Box 3000, Boulder, CO 80307 United States
AU: Mueller, D
EM: detlef@tropos.de
AF: Institute for Tropospheric Research, Permoserstr 15 , Leipzig, 04318 Germany
AU: Seifert, P
EM: seifert@tropos.de
AF: Institute for Tropospheric Research, Permoserstr 15 , Leipzig, 04318 Germany
AB: We have analyzed MODIS satellite data, surface lidar, and air trajectories over India and the Indian Ocean to assess the influence of aerosols upon cloud reflectance as a function of cloud top pressure. Our hypothesis was that the aerosol indirect effect would extend throughout the troposphere for both liquid cloud droplets and cloud ice crystals that are present in convective clouds. The satellite data at 1.38 and 3.75 microns show an aerosol indirect effect for liquid clouds that is consistent with previous in-situ microphysical measurements. However, the satellite data do not indicate the presence of an indirect effect in the upper troposphere for cloud ice crystals, although we could only ascertain this result for clouds with optical depths greater than unity. We applied the Disort multiple scattering code to calculate aerosol direct effects, i.e. changes in cloud reflectance solely due to changes in aerosol optical depth. The observed changes in cloud reflectance in the lower troposphere are larger than those due to aerosol direct effects.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0321 Cloud/radiation interaction
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005