HR: 0800h
AN: A21E-0778    [Abstracts]
TI: Lidar cirrus cloud and aerosol measurements in the tropopause region
AU: Chen, W
EM: wnchen@rcec.sinica.edu.tw
AF: National Central University, Department of Physics, ChungLi, 32054, Taiwan
AU: Chiang, C
EM: cwchiang@alumni.ncu.edu.tw
AF: National Central University, Department of Physics, ChungLi, 32054, Taiwan
AU: * Nee, J
EM: jbnee@phy.ncu.edu.tw
AF: National Central University, Department of Physics, ChungLi, 32054, Taiwan
AB: Cirrus cloud can be formed in the upper troposphere by ice particles through nucleation processes. Currently, it is not well understood about the details of the homogeneous or heterogeneous processes. The nucleation of cirrus clouds by sulfate aerosols has been suggested as a possible path. By using a lidar at 532 nm, cirrus cloud and stratospheric aerosol (SA) in the UT/LS are measured. Polarization measurements were employed to distinguish their difference of particle shapes. Lidar backscattering coefficients shows an anti-correlation between both. This suggests that more or larger aerosol particles result in small cirrus cloud particles. The cirrus clouds in the tropopause region are also compared with HALOE cirrus cloud and water vapor data. Results show that in summer months higher probability for observation cirrus clouds is caused by the presence of water vapor in the tropopause region.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0321 Cloud/radiation interaction
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting