The information offered by the satellite images will be used by scientists working on the Surface Heat Budget of the Arctic Ocean Project (SHEBA), jointly sponsored by the US, Canadian and Japanese governments.
Part of the project involved deliberately trapping a Canadian icebreaker in ice for a full year to allow measurements of the atmosphere, ocean and ice to be taken. The newly-declassified images show the area around the icebreaker over several months.
Initial SHEBA findings show that the Arctic ice sheet is about 5% smaller and one metre thinner than it was in the 1970s. Scientists fear that continued shrinkage of the ice sheet could accelerate global warming. This is because ice reflects solar radiation to a greater extent than do ocean waters.
Al Gore acknowledged the threat posed by reductions in the arctic ice sheet when he announced the release of the 59 satellite images. “No place on earth is more sensitive to global warming than the Arctic,” he said.