Circulation and Heat Fluxes during the
Austral Fall in George VI Sound, Antarctic Peninsula
Ryan D. Dorland and Meng Zhou
University of Massachusetts, Boston, Boston, MA 02125, USA
Abstract
An intensive mesoscale survey was conducted in northern
George VI Sound as part of the US Southern Ocean GLOBEC program in the austral
fall, 2001 to determine the hydrography and its
impacts on the Antarctic winter ecosystem.
The absolute dynamic height field estimated from a combination of ADCP
and CTD data reveals coastal jets intruding from Marguerite Bay and mesoscale
eddies entrained within the sound.
Temperature and salinity measurements indicate the presence of the
modified Circumpolar Deep Water throughout the survey area. Vertical velocities were computed based on
quasi-geostrophic dynamics revealing vertical
circulation cells associated with the coastal mesoscale
jets and eddies. Heat fluxes determined
from horizontal and vertical advection of temperature gradients were comparable
to surface heat fluxes that are critical to local ice formation. The revealed coastal currents and eddies
created the physical and biological environment favorable for the survival of
higher trophic seabirds and mammals during austral
winter in Marguerite Bay.
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