Open AccessOn the dynamics of Atlantic Water circulation in the Arctic Ocean
Author(s) -
Karcher M.,
Kauker F.,
Gerdes R.,
Hunke E.,
Zhang J.
Publication year - 2007
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006jc003630
Subject(s) - ocean gyre , geology , climatology , oceanography , arctic , halocline , thermohaline circulation , ocean current , arctic dipole anomaly , arctic sea ice decline , canada basin , arctic ice pack , drift ice , salinity , subtropics , fishery , biology
We use a subset of models from the coordinated experiment of the Arctic Ocean Model Intercomparison Project (AOMIP) to analyze differences in intensity and sense of rotation of Atlantic Water circulation. We focus on the interpretation of the potential vorticity (PV) balance. Results differ drastically for the Eurasian and the Amerasian Basins of the Arctic Ocean. We find indications that in the Eurasian Basin the lateral net flux of PV is a significant factor for the determination of the sense of rotation of Atlantic Water circulation on timescales beyond pentades. The main source of high PV causing cyclonic circulation in the Eurasian Basin is the Barents Sea, where the seasonal cycle of surface buoyancy fluxes forms stratified water that leaves the shelf and feeds the Atlantic Water Layer (AWL) in the Arctic Basins. However, in the Amerasian Basin vertical PV fluxes are the more important factor. These are closely related to wind field changes. We find an intense response of the AWL flow to wind forcing, approximated by the sea level pressure difference between the Bering Sea and the central Canadian Basin, which describes about half the variance of AWL flow of the Amerasian Basin. An experiment driven with a repeated atmospheric climatology exhibits an extreme case where a permanent high pressure system over the Beaufort Sea dominates the circulation in the Amerasian Basin, demonstrating the potential of the Beaufort Gyre to adjust in such a way as to suppress a cyclonic AWL flow in the Amerasian Basin. In more realistic cases the Beaufort Gyre still modulates the Amerasian Basin AWL circulation significantly.