Dynamics of the Antarctic Circumpolar Current. Evidence for Topographic Effects from Altimeter Data and Numerical Model Output.

Geosat altimeter data and numerical model output are used to examine the circulation and dynamics of the Antarctic Circumpolar Current (ACC). The mean sea surface height across the ACC has been reconstructed from height variability measured by the altimeter, without assuming prior knowledge of the g...

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Bibliographic Details
Main Author: Gille, Sarah T.
Other Authors: MASSACHUSETTS INST OF TECH CAMBRIDGE
Format: Text
Language:English
Published: 1995
Subjects:
Physical and Dynamic Oceanography
*OCEAN CURRENTS
*EDDIES(FLUID MECHANICS)
*OCEANOGRAPHIC DATA
HEAT TRANSFER
PRESSURE GRADIENTS
MATHEMATICAL MODELS
POLAR REGIONS
SPATIAL DISTRIBUTION
OCEAN SURFACE
ANALYSIS OF VARIANCE
THESES
INPUT OUTPUT PROCESSING
VORTICES
HIGH RESOLUTION
CONTINENTAL SHELVES
BATHYMETRY
KINETIC ENERGY
ALTIMETERS
DRAG
MARINE CLIMATOLOGY
HYDROGRAPHY
STRATIFICATION
OCEAN MODELS
GEOSTROPHIC WIND
OCEAN BOTTOM TOPOGRAPHY
REYNOLDS NUMBER
WIND STRESS
EQUATIONS OF STATE
FRONTS(OCEANOGRAPHY)
ANTARCTIC REGIONS
MOMENTUM TRANSFER
JET STREAMS
SCIENTIFIC SATELLITES
SOUTHERN OCEAN
Antarctic
Southern Ocean
The Antarctic
Antarc*
Online Access:http://www.dtic.mil/docs/citations/ADA305871
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA305871
Description
Summary:Geosat altimeter data and numerical model output are used to examine the circulation and dynamics of the Antarctic Circumpolar Current (ACC). The mean sea surface height across the ACC has been reconstructed from height variability measured by the altimeter, without assuming prior knowledge of the geoid. The results indicate locations for the Subantarctic and Polar Fronts which are consistent with in situ observations and indicate that the fronts are substantially steered by bathymetry. Detailed examination of spatial and temporal variability indicates a spatial decorrelation scale of 85 km and a temporal e-folding scale of 34 days. Empirical Orthogonal Function analysis suggests that the scales of motion are relatively short, occuring on 1000 km length-scales rather than basin or global scales. The momentum balance of the ACC has been investigated using output from the high resolution primitive equation model in combination with altimeter data. In the Semtner-Chervin quarter-degree general circulation model topographic form stress is the dominant process balancing the surface wind forcing. In stream coordinates, the dominant effect transporting momentum across the ACC is bibarmonic friction. Potential vorticity is considered on Montgomery streamlines in the model output and along surface streamlines in model and altimeter data. (AN) Prepared in cooperation with Woods Hole Oceanographic Inst., MA.

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