Arctic Water Body Dynamics: A pan-Siberian Study of Seasonal Changes in Inundation
Trofaier, Anna Maria1; Rees, William Gareth1; Bartsch, Annett2
1Scott Polar Research Institute, University of Cambridge, UNITED KINGDOM; 2Vienna University of Technology, AUSTRIA
Remote sensing of Arctic water bodies is an essential method for monitoring the dynamics of frozen ground. Thaw lake change provides insight into the state of permafrost. In the vast Arctic and sub-Arctic areas capturing changes in lake extent is assisted by the use of satellite data. In particular, active microwave sensors can be used in a straightforward manner for water body classifications.
This study uses the pan-Siberian datasets that are produced and provided under the ESA STSE-ALANIS methane project. The project's Local Wetlands product is a suite of 10-day binary surface water classifications that are produced using Envisat ASAR (Advanced Synthetic Aperture Radar) operating in wide swath mode (spatial resolution 150m). The high temporal frequency of these data allows an investigation of surface hydrology on an intra-annual basis. The need for understanding and quantifying lake change within the short Arctic spring/summer season has become more apparent. The dynamics of seasonal inundation may affect analysis of decadal lake change if these flood patterns are not taken into account.
The current study applies a post-processing algorithm to the Local Wetlands product in order to investigate changes in surface inundation across Siberia over the spring/summer period of 2007/2008. Multiple areas across Siberia are found to exhibit seasonal changes in surface inundation. QuikSCAT data are used to deduce timings of snowmelt that can be correlated with spring floods. These floods and any associated temporal patterns are identified. The patterns are mapped and changes in water body extent are quantified.