Ice and water
Each winter, about 4 million square kilometres of Canadian waters are covered in ice, and 40,000 icebergs migrate through Canada’s eastern waters. So it’s not surprising that the biggest user of satellite imagery from the RADARSAT program is the Canadian Ice Service, which provides daily updates on the ice conditions in navigable waters. Radar data can provide a surprising amount of information about the nature of ice. For example, new sea ice is smooth and relatively thin, making it less dangerous to ships, and it appears dark in radar imagery. Older ice tends to be thicker, making it more dangerous, and it has a lower salt content, making it appear brighter to the radar.
Satellites can also be useful for monitoring open water, since wind and waves affect the surface roughness of the ocean in a way that is visible to remote sensors. This information can assist in offshore oil exploration, and in locating productive fishing areas. Satellites can also detect ships, a feature exploited by Canada’s space-based surveillance program, Polar Epsilon. A particular advantage of radar is that it sees through clouds and in the dark, so these observations can taken at any time of day or night, no matter what the weather conditions.
This interactive show contains three different time-lapsed animations from 2007 and 2008. Selected through buttons below, each illustrates rapid ice shelf loss; the first along Ellesmere Island, and the second and third off the Ward Hunt Ice Shelf, the largest ice shelf in the northern hemisphere.