The 5th Conference on Polar Meteorology and Oceanography

9.2
NEW CLIMATOLOGIES OF POLAR CLOUDS AND RADIATION BASED ON THE ISCCP

Jeffrey Key, Boston University, Boston, MA; and D. Slayback, C. Xu, and A. Schweiger

The new cloud product of the International Satellite Cloud Climatology Project (ISCCP), termed the "D" dataset, is being generated with an improved cloud detection algorithm for the polar regions. At present, six years of the new product are available (1986, 1989-1993). In the "D" product cloud amounts are higher and cloud optical depths are lower; both are thought to be changes in the right direction. Here we update our previous analyses of the "C" product, where significant discrepancies between satellite-derived and surface observations of cloud amount, cloud type, and surface radiative fluxes were found. Spatial and temporal patterns of cloud properties given directly in the ISCCP D1 (3-hourly) and D2 (monthly) products are summarized for the Arctic and Antarctic, relationships between cloud properties such as optical depth and temperature are illustrated, and correlations with large-scale heat and moisture fluxes are examined. Surface and top-of-the-atmosphere radiative fluxes and cloud "forcings" are computed from the 3-hourly data and summarized. Potential problems in the cloud product are briefly described.

The 5th Conference on Polar Meteorology and Oceanography