Diurnal thaw and refreeze during spring snowmelt from QuikScat over entire Siberia

Abstract submitted to "5th Workshop on Remote Sensing of Land Ice and Snow"

A sensitivity and time series analyses

Annett Bartsch

ab at ipf dot tuwien dot ac dot at

{Vienna University of Technology, Institute of Photogrammetry and Remote Sensing} {}

http://www.ipf.tuwien.ac.at/ab

Richard A. Kidd

{Spatial Information and Mapping Centre, Banda Aceh} {}

Wolfgang Wagner

{Vienna University of Technology, Institute of Photogrammetry and Remote Sensing} {}

Keywords: snowmelt; scatterometer; change detection

Presentation preference: oral

The adaptive, diurnal difference, approach developed for Seawinds/QuikScat data over central Siberia allows the determination of the length of the final period of diurnal thaw/refreeze. This duration and the spatial dynamics are closely linked to surface hydrology and ecosystem processes.
The approach has been transferred to entire Russia (>55°N) and the sensitivity assessed. This revealed that some tundra regions are characterized by multiple periods of consecutive days with diurnal thaw and refreeze during spring snowmelt. This needs to be taken into consideration for monitoring of such vast areas spanning several biomes.
Time series analysis (2000 2005) based on the improved snowmelt maps indicates different trends within the boreal, subarctic and arctic environments. They vary for the onset, the duration and the end of snowmelt. This impacts seasonal carbon sequestration dynamics as well as spring/early summer runoff which is directly related to spatial patterns of thaw in the high latitudes.

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