HR: 08:15h
AN: C21C-02 INVITED    [Abstracts]
TI: In Situ Thickness Observations of Sea Ice and Snow in the Fram Strait
AU: * Gerland, S
EM: gerland@npolar.no
AF: Norwegian Polar Institute, Polar Environmental Centre, Tromso, 9296, Norway
AU: Haas, C
EM: chaas@ualberta.ca
AF: Alfred Wegener Institute for Polar and Marine Research, P.O. Box 120161, Bremerhaven, 27515, Germany
AU: Haas, C
EM: chaas@ualberta.ca
AF: University of Alberta, Earth and Atmospheric Sciences, Edmonton, T6G 2E1, Canada
AU: Goodwin, H
EM: goodwin@npolar.no
AF: Norwegian Polar Institute, Polar Environmental Centre, Tromso, 9296, Norway
AU: Nicolaus, M
EM: marcel.nicolaus@npolar.no
AF: Norwegian Polar Institute, Polar Environmental Centre, Tromso, 9296, Norway
AU: Nicolaus, A
EM: anja.nicolaus@npolar.no
AF: Norwegian Polar Institute, Polar Environmental Centre, Tromso, 9296, Norway
AU: Hansen, E
EM: edhan@npolar.no
AF: Norwegian Polar Institute, Polar Environmental Centre, Tromso, 9296, Norway
AU: Renner, A H
EM: ahhre@bas.ac.uk
AF: Norwegian Polar Institute, Polar Environmental Centre, Tromso, 9296, Norway
AU: Renner, A H
EM: ahhre@bas.ac.uk
AF: British Antarctic Survey, Natural Environmental Research Council Madingley Road, Cambridge, CB3 0ET, United Kingdom
AB: The Fram Strait, at the end of the transpolar drift is the main gateway for multiyear sea ice exiting the Arctic Basin. Knowledge about sea ice in the Fram Strait gives information on the general state of high-arctic sea ice. In particular, sea ice mass balance can be derived from knowing ice concentration, extent and thickness. Since 2003, we regularly carry out in situ sea ice surveys in the Fram Strait. Sea ice thickness data were collected yearly in September and during two spring cruises in 2005 and 2007. Ice and snow thickness is measured along profiles by ground-based electromagnetics and drillings. In May 2005, additional profiles were obtained using airborne helicopter electromagnetics. Sea ice observed in September in the Fram Strait is commonly multiyear ice with modal total thicknesses (ice plus snow) between 2.25 and 3.25 m. Snow thickness is generally small, since only a small amount of new snow accumulated after the summer melt (modal snow thickness between 0.02 and 0.11 m). Whereas the majority of the ice drifts relatively fast in a SSW direction, grounded icebergs function as islands on the Greenland Shelf, resulting in multiyear fast ice forming in their vicinity. Spring surveys reveal substantial amounts of snow covering both first- and multiyear ice. With airborne thickness profiling, a gradient of increasing modal total thickness from east (1.65 m) to west (3.25 m) could be identified. The different sea ice regimes in the Fram Strait represent ice of different age and origin. It is planned to monitor possible trends in ice thickness by continuing the surveys, combined with continuous ice draft data obtained from moored upward looking sonars.
DE: 0736 Snow (1827, 1863)
DE: 0750 Sea ice (4540)
DE: 0762 Mass balance (1218, 1223)
DE: 1621 Cryospheric change (0776)
DE: 9315 Arctic region (0718, 4207)
SC: Cryosphere [C]
MN: 2007 Fall Meeting