HR: 11:20h
AN: A42C-06 INVITED    [Abstracts]
TI: Using A-Train observations to constrain and improve arctic cloud parameterizations
AU: * Kay, J E
EM: jenkay@ucar.edu
AF: National Center for Atmospheric Research, NCAR/CGD PO Box 3000, Boulder, CO 80307, United States
AU: Gettelman, A
EM: andrew@ucar.edu
AF: National Center for Atmospheric Research, NCAR/CGD PO Box 3000, Boulder, CO 80307, United States
AU: Morrison, H
EM: morrison@ucar.edu
AF: National Center for Atmospheric Research, NCAR/CGD PO Box 3000, Boulder, CO 80307, United States
AB: Many climate models appear to have significant biases in their representation of Arctic climate, but there is a dearth of reliable cloud observations to help constrain climate model parameterizations. A-Train observations provide a unique and useful tool for investigating the spatial distribution and the physical properties of Arctic clouds. We use A-Train radar (CloudSat) and lidar (CALIOP) observations to map Arctic cloud fraction, cloud top height, cloud thickness, and radar reflectivity from July 2006 to present. We also investigate the relationship between Arctic cloud properties and sea ice cover (AMSR-E). Using these new observations, we evaluate the representation of Arctic clouds in a state-of-the-art climate model, the Community Atmosphere Model (CAM). We present model-observation comparisons using traditional geophysical variables, as well as comparison of the raw observations to model-simulated observations (e.g., model-simulated radar reflectivity). Finally, we evaluate the sensitivity of modeled Arctic clouds to the paramterization of clouds and the atmospheric boundary layer.
UR: http://www.cgd.ucar.edu/cms/jenkay/
DE: 1626 Global climate models (3337, 4928)
DE: 1855 Remote sensing (1640)
DE: 3310 Clouds and cloud feedbacks
DE: 9315 Arctic region (0718, 4207)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting