HR: 14:45h
AN: OS33C-04    [Abstracts]
TI: Change in Beaufort Sea Ice in the 1990s: A Perspective Based on Thickness
AU: * Melling, H
EM: MellingH@dfo-mpo.gc.ca
AF: Fisheries and Oceans Canada, Institute of Ocean Sciences P.O. Box 6000, Sidney, BC V8L 4B2 Canada
AU: Riedel, D A
EM: RiedelD@dfo-mpo.gc.ca
AF: Fisheries and Oceans Canada, Institute of Ocean Sciences P.O. Box 6000, Sidney, BC V8L 4B2 Canada
AB: A 12-year series of ice-draft measurements by sonar in the eastern Beaufort Sea provides opportunity to examine the impact of the warm 1990s in this area. The results are perhaps surprisingly. The average thickness of ice has changed little. The average ice coverage has changed little, although the coverage by old ice has increased slightly. The year 1998 stands out clearly as an anomaly. There is a large variation in average ice draft throughout the year which is driven by seasonally varying ice drift as well as by the annual cycle of freezing and melting. Inter-annual variation in average ice draft is also large, forced primarily by the impact of changes in average wind on ice circulation. However, year-to-year variation in storminess also appears important, through its impact on the flaw lead and on ridging along the coastal margin. The negligible trend in the average draft of the predominately first-year pack of this area is consistent with data for coastal sea ice over a wide area across northern Eurasia and North America, which span a half century. The trend may also be consistent with recent change in the thickness of pack ice in the central Arctic Ocean, when first-year and multi-year ice are examined separately.
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4207 Arctic and Antarctic oceanography
DE: 4215 Climate and interannual variability (3309)
DE: 1863 Snow and ice (1827)
DE: 1635 Oceans (4203)
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting