On the Effectiveness of the Production of Antarctic Bottom Water in the Weddell and Ross Seas

The northward propagation of Antarctic Bottom Water AABW, from its primary source in the Weddell Sea, has been documented since the early part of this century. Despite the striking similarities between the Weddell and the Ross Seas, AABW is mainly produced in the Weddell Sea. The question is posed as to why the Weddell Sea is so effective in the production of AABW as compared to the Ross Sea. Differences are determined by analyzing various physical mechanisms and forcing functions in both basins with respect to the two predominant theories of AABW formation. Foster and Carmacks shelf break process theory and Foldvik and Gammelsrods theory of ice shelf processes. Results reveal that the strong tidal forcing at the Weddell Sea ice shelf barrier combines with the wind stress field and with the special under-ice-shelf and continental shelf bathymetrics of the Weddell Sea to become the critical elements of the AABW formation process. The shelf theory is found to account for the formation of Weddell Sea Bottom Water WSBW, the parent constituent of AABW, with a prediction of an Ice Shelf Water outflow rate of approximately 0.7 x 1,000,000 m3s-1 due to tidal action at the barrier allowing ice production by high surface freezing levels and tidal forcing of sea water under the ice shelf and a production rate of WSBW of 5 x 1,000,000 m3s-1 which agrees with observations and current estimates. Keywords Antarctic Weddell sea Ross sea Bottom water Ocean dynamics Ocean currents Military theses.