Seasonality in the Response of Sea Ice to Wind Forcing on the Mackenzie Shelf, Arctic Ocean , and Consequences to Upwelling Under the Scenario of Climate Warming

HR: 1340h
AN: OS43B-1242 [Abstracts]
TI: Seasonality in the Response of Sea Ice to Wind Forcing on the Mackenzie Shelf, Arctic Ocean , and Consequences to Upwelling Under the Scenario of Climate Warming
AU: * Wang, Q
EM: qwang@eos.ubc.ca
AF: Department of Earth and Ocean Sciences, UBC., 6339 Stores Rd., Vancouver, BC V6T2G9, Canada
AU: Ingram, G
EM: gingram@eos.ubc.ca
AF: Department of Earth and Ocean Sciences, UBC., 6339 Stores Rd., Vancouver, BC V6T2G9, Canada
AU: Williams, W
EM: WilliamsBi@pac.dfo-mpo.gc.ca
AF: Institute of Ocean Sciences, Canada, 9860 West Sannich Road, Sidney, BC V8L 4N2, Canada
AU: Carmack, E
EM: CarmackE@pac.dfo-mpo.gc.ca
AF: Institute of Ocean Sciences, Canada, 9860 West Sannich Road, Sidney, BC V8L 4N2, Canada
AB: Seasonal pattern of ice motion in response to wind forcing and potential consequences to upwelling on the Mackenzie Shelf are considered using satellite-derived ice motion data from the National Snow and Ice Data Center and the NCEP 10 m wind data. The frequency of strong upwelling-favorable alongshore ice motion is high in early winter (November and December) compared to middle and late winter (January to May). For periods when the alongshore component of the wind is upwelling-favorable, the ratio of ice drift divided by wind speed on the Mackenzie Shelf is 0.024 in November and 0.008 in March; we conjecture that this ratio decreases as winter progresses because the internal ice stress becomes stronger as both ice thickness and ice concentration increase. This constitutes a possible 10-fold decrease in the seasonal transmission of wind stress to the underlying water from November to March. Conversely, this ratio in May (0.015) is higher than that in March. We suggest that it is because the internal ice stress becomes weaker as ice concentration decreases on the Mackenzie Shelf in May. Hence, under the same wind forcing, the potential for winter upwelling on Mackenzie Shelf may be enhanced if climate warming results in reduced ice thickness and/or ice concentration. A major unknown remains the effective coupling of wind to water as ice concentration and relative roughness decrease.
DE: 4500 OCEANOGRAPHY: PHYSICAL
DE: 4540 Ice mechanics and air/sea/ice exchange processes (0700, 0750, 0752, 0754)
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting