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Observations of the Antarctic Slope Undercurrent in the southeastern Weddell Sea
Author(s) -
Chavanne Cédric P.,
Heywood Karen J.,
Nicholls Keith W.,
Fer Ilker
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl043603
Subject(s) - geology , oceanography , hydrography , continental shelf , pycnocline , submarine pipeline , current (fluid) , ice shelf , weddell sea bottom water , front (military) , sea ice , cryosphere
The Antarctic Slope Front presents a dynamical barrier between the cold Antarctic shelf waters in contact with ice shelves and the warmer subsurface waters offshore. Two hydrographic sections with full‐depth current measurements were undertaken in January and February 2009 across the slope and shelf in the southeastern Weddell Sea. Southwestward surface‐intensified currents of ∼30 cm s −1 , and northeastward undercurrents of 6–9 cm s −1 , were in thermal‐wind balance with the sloping isopycnals across the front, which migrated offshore by 30 km in the time interval between the two sections. A mid‐depth undercurrent on February 23 was associated with a 130‐m uplift of the main pycnocline, bringing Warm Deep Water closer to the shelf break. This vertical displacement, comparable to that caused by seasonal variations in wind speed, implies that undercurrents may affect the exchanges between coastal and deep waters near the Antarctic continental margins.