ABSTRACT

This collaborative study will analyze the antarctic oceanographic dataset obtained during the three-year Antarctic Slope Front Project ("AnSlope"), whose objective was to identify and quantify the principal physical processes governing the transfer of dense antarctic shelf waters into intermediate and deep layers of the adjacent deep ocean, and the compensatory poleward flow of open ocean waters across the shelf break. Research activities will be organized around: (i) a full description of the northwestern Ross Sea slope front region including the structure of the slope front and the energetic outflows of dense shelf water; and (ii) detailed study of the dynamics of cross-frontal exchange and their relationship to environmental forcing (ocean, sea ice, atmosphere). The work will evaluate the spatial and temporal scales of the descending dense outflows that originate in different shelf troughs; the roles of entrainment, thermobaricity, and benthic stress on the dilution, descent and spreading of the outflows; and the primary mechanisms driving on-shelf intrusions and cross-isobath motions. Ultimately, modeling studies guided by the data interpretation will facilitate the development of parameterizations of cross-slope exchanges in global ocean models.
While the importance of cold water masses originating in the Antarctic to the global ocean circulation and climate is unquestioned, the processes by which these water masses enter the deep ocean circulation are not. The upper continental slope around Antarctica has been identified as the primary gateway for the exchange of shelf and deep ocean waters. Here the topography, velocity and density fields associated with the nearly ubiquitous front must strongly influence the advective and turbulent transfer of water properties between the shelf and oceanic regimes. The strength and variability of this gateway is critical in maintaining the structure of the world ocean.

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