IARC Seminar Announcement

Submitted by Kimberly Hayes
Phone: 907-474-7176

10/07/05

Title: Seasonal Variation of Snow Surface Properties in the Northern Hemisphere Captured by GLI

Presentor: Masahiro Hori Earth Observation and Application Center, JAXA

Tuesday, October 25, 2005

IARC, Conference Room 401 1:30 p.m.

ABSTRACT

Snow physical parameters, such as snow grain size and mass fraction of impurities mixed in the snow layer, are important factors that determine spectral albedo of the snow surface. Thus, it is essential to monitor those parameters from space in order to study the response of snow and sea-ice cover extent in the Polar Regions to a climate forcing, such as global warming. The optical sensor Global imager (GLI) onboard the Japanese earth observing satellite ADEOS-II, which was launched in December 2002 and unfortunately stopped operation in October 2003, observed temporal and spatial variations of snow grain size and snow impurities, as well as snow/sea-ice covered areas on a global scale. A 7-month GLI data analysis reveals that the spatial distributions of snow grain size in the arctic regions exhibit significant latitudinal dependence and change drastically from season to season, in response to the changes of snow surface temperature. The retrieved results of snow impurities show that mass fractions are low in the Arctic and high at mid-latitude regions. However, many factors such as vegetation cover, less snow depth etc., still seem to affect the accuracy of the retrieved snow impurities. Although the truth data for validating those retrieved snow surface properties are still limited, the results are expected to provide useful information that is required to improve the treatment of land processes in regional and global climate models.