Shallow freshwater lakes cover a large portion of the Canadian Arctic and sub-Arctic landscape. Lake and river ice cover are major components of the cryosphere, and their phenology affects both natural processes and human activities. The sensitivity of both lake and river ice to air temperature makes them both useful indicators of climate change in the north. Lake and river ice are also components of ice roads, providing winter access to remote northern locations that lack a land-based road network.
Surface monitoring of Arctic and sub-Arctic lakes and rivers is not practical, due to their remote location and vast number. Therefore, satellite imaging, specifically with SAR, is the best means of mapping and monitoring lake ice. For repeat measurements (every few days in some cases), satellite imagery is the most practical.
Techniques developed at the Canada Centre for Mapping and Earth Observation are now being used across Canada to monitor the timing and related dynamics of lake and river ice freeze-up and break-up. In the north, this information supports the safe use of seasonal ice roads, improves flood and weather prediction and help secures nearby infrastructure.