HR: 0800h
AN: C11B-0441    [Abstracts]
TI: Short Term Variability of Sea Ice Thickness in the Beaufort Sea
AU: * Hendricks, S
EM: stefan.hendricks@awi.de
AF: Alfred Wegener Institute for Polar and Marine Research, Bussestr. 24, Bremerhaven, 27568, Germany
AU: Hutchings, J
EM: jenny@iarc.uaf.edu
AF: University of Alaska Fairbanks, International Arctic Research Center, 930 Koyukuk Drive, Fairbanks, AK 99775, United States
AB: To investigate the relationship between variability of sea ice thickness and ice dynamics, helicopter borne electromagnetic sea ice thickness sounding was performed at the APLIS ice camp in the Beaufort sea in April 2007. The field campaign includes sea ice thickness observations close to the camp with repeated flight tracks of different length scales and a transect ranging from 75°N to the coast of Barrow, Alaska at 71.2°N. In total sea ice thickness with a point spacing of 3-4 meters was obtained on profiles with a total length of more than 2000 km. The data comprises changes in the ice thickness distribution in spatial scales up to 100 km at a time period of nearly two weeks close to the camp. The deformation of the sea ice field in the vicinity of the ice camp was covered by two arrays of GPS drifting buoys yielding the drift and rotation of the ice field. The most recent positions of these buoys were used as waypoints for the ice thickness observations, which guarantees the comparability of the successive profiles. The modal ice thickness around the ice camp did not change significantly in the time range of the field campaign. The modal ice thickness including the snow depth of the first year ice amounts to 1.7 m, while the multiyear ice was about 2.6 m thick. Changes due to the dynamics of the ice pack can be observed in the mean ice thickness which decreased by roughly 10 cm in a time span of 9 days (2.70 m to 2.59 m). This decrease can be explained by a higher fraction of newly formed ice in the thickness distribution due to strong winds, which exceeded the similar increased contingent of deformed ice in the ice thickness distribution. At the regional scale no significant trend in the sea ice thickness could be observed between the coast and the northernmost point, showing that the surveyed sea ice was of the same age in the whole measurement area. Differences could only be observed in the fraction of open water and the deformation rate between the coastal zone and the central Beaufort Sea.
DE: 0750 Sea ice (4540)
DE: 0762 Mass balance (1218, 1223)
DE: 0772 Distribution
DE: 0774 Dynamics
SC: Cryosphere [C]
MN: 2007 Fall Meeting