Thoma, Jenkins, Holland, Jacobs: Modelling Circumpolar Deep Water intrusions on the Amundsen Sea continental shelf, Antarctica

Geophysical Research Letters, 2008, Vol. 35, L18602; doi:10.1029/2008GL034939

Modelling Circumpolar Deep Water intrusions on the Amundsen Sea continental shelf, Antarctica

Malte Thoma (British Antarctic Survey, Natural Environment Research Council, Cambridge, U.K.), Adrian Jenkins (British Antarctic Survey, Natural Environment Research Council, Cambridge, U.K.), David Holland (Courant Institute of Mathematical Sciences, New York University, New York, NY, U.S.A.), and Stan Jacobs (Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, U.S.A.)

Abstract

Results are presented from an isopycnic coordinate model of ocean circulation in the Amundsen Sea, focusing on the delivery of Circumpolar Deep Water (CDW) to the inner continental shelf around Pine Island Bay. The warmest waters to reach this region are channeled through a submarine trough, accessed via bathymetric irregularities along the shelf break. Temporal variability in the influx of CDW is related to regional wind forcing. Easterly winds over the shelf edge change to westerlies when the Amundsen Sea Low migrates west and south in winter/spring. This drives seasonal on-shelf flow, while inter-annual changes in the wind forcing lead to inflow variability on a decadal timescale. A modelled period of warming following low CDW influx in the late 1980's and early 1990's coincides with a period of observed thinning and acceleration of Pine Island Glacier.

(Received 6 June 2008; accepted 7 August 2008; published 18 September 2008.)

Key words: Amundsen Sea, Circumpolar Deep Water, continental shelf

Index Terms: 4207 Oceanography: General: Arctic and Antarctic oceanography (9310, 9315); 4219 Oceanography: General: Continental shelf and slope processes (3002); 4255 Oceanography: General: Numerical modeling (0545, 0560); 0728 Cryosphere: Ice shelves; 1621 Global Change: Cryospheric change (0776).

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Citation: Thoma, M., A. Jenkins, D. Holland, and S. Jacobs (2008), Modelling Circumpolar Deep Water intrusions on the Amundsen Sea continental shelf, Antarctica, Geophys. Res. Lett., 35, L18602, doi:10.1029/2008GL034939.

Link to abstract: http://www.agu.org/pubs/crossref/2008/2008GL034939.shtml