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 an d early 1990s. No similar trend was evident in ice drafts near the North Po le. The 1980s drafts were composed largely of ice exceeding 3.5 m, while th e early 1990s drafts contained more ice in thinner categories. The differen ces in drafts between the two periods appear to be related largely to ice d ynamics effects associated with the presence and strength of the Beaufort G yre, which weakened considerably in the early 1990s.