Evidence for rapid thinning of sea ice in the western Arctic Ocean at the end of the 1980s

Examination of springtime ice drafts obtained from submarine profiles in a narrow band of the western Arctic Ocean from offshore Alaska to 89 degreesN indicates that the mean ice draft decreased 1.5 m between the mid-1980s and early 1990s. No similar trend was evident in ice drafts near the North Pole. The 1980s drafts were composed largely of ice exceeding 3.5 m, while the early 1990s drafts contained more ice in thinner categories. The differences in drafts between the two periods appear to be related largely to ice dynamics effects associated with the presence and strength of the Beaufort Gyre, which weakened considerably in the early 1990s.