Satellite-derived evolution of Arctic sea ice age: October 1978 to March 2003

Combining gridded ice motions with daily ice extent maps, it is possible to "track" the evolution of sea ice in the Arctic region. Classifying the ice by ice age, this evolution reveals that the area of the oldest (>4 years) ice is decreasing in the Arctic Basin and is being replaced by younger, first-year ice. As a result, the extent of the oldest ice retreats to a relatively small area north of the Canadian Archipelago, with narrow bands that spread out across the central Arctic. This new approach reinforces the work done by others showing the changes in the Arctic sea ice cover over the past two decades.