Observational Evidence of Recent Changes in the Ice Regime of High Arctic Lakes from Space-Borne SAR
Surdu, Cristina¹; Duguay, Claude R.¹; Fernandez Prieto, Diego^2
1University of Waterloo, CANADA; ²ESA, ITALY

Climate-driven changes have significantly impacted the high latitude environments over the past recent decades, changes that are predicted to continue or even accelerate in the near future as projected by global climate models. Following warmer climate conditions, the Arctic lake ice cover is expected to continue reducing in both, duration and extent, and consequently alter water balance, mixing regimes, biological, physical and chemical processes. In the case of lakes in the Canadian Arctic Archipelago, many of which are ice covered more than ten months per year, warmer temperatures could result in fewer lakes that develop perennial ice cover, earlier break-up dates, and shorter ice seasons. Lake ice regime shifts have been identified across the Arctic but considering the limited availability of resources to monitor High Arctic lakes, past and ongoing changes within these lakes have not yet been comprehensively documented.

In the context of ESA's STSE North Hydrology project, a 15-year time series of RADARSAT-1/2 and ENVISAT ASAR wide-swath synthetic aperture radar (SAR) data was analyzed to detect the response of ice cover on lakes in the Canadian Arctic Archipelago to climate conditions during recent years. Preliminary results indicate that the ice cover of lakes situated in a typical polar desert environment as well as that of lakes in a milder polar oasis climate may be transitioning from a perennial to a seasonal ice regime, with earlier ice off dates consequent to the loss of perennial ice, and an overall deficit in ice duration. Available meteorological records were also examined to identify the evidence of change that warmer climate conditions in the western Canadian Arctic may have had upon the ice cover of these lakes when compared to the colder eastern High Arctic.