Formation and circulation of ice shelf water in the Weddell and Ross Seas
Ole Anders Nøst
Department of Geophysics, University of Bergen, Norway. December 1995
Contents
List of papers
Introduction
Motivation for the present work
Background
Circulation on the Weddell Sea Continental Shelf
Circulation on the Ross Sea Continental Shelf
Ice shelf-ocean interaction
Outline of the thesis
Future work
References
List of Papers
Paper 1: O.A. Nøst, and A. Foldvik, A model of ice shelf-ocean interaction with application to the Filchner-Ronne and Ross Ice Shelves, J Geophys. Res., VOL 99, 14243-14254, 1994.
Paper 2: Gammelsrød T., A. Foldvik, O.A. Nøst, Ø. Skagseth, L.G. Anderson, E. Fogelquist, K. Olsson, T. Tanhua, E.P. Jones, and S. Østerhus, Distribution of water masses onthe continental shelf in the southern Weddell Sea, in "The polar oceans and their role in shaping the global environment", A G U Geophysical Monograph 84, 1994.
Paper 3: Nøst, O.A., and S. Østerhus, Impact of grounded icebergs on the hydrographic conditions near Filchner Ice Shelf, Antarctica, Submitted to J Geophys. Res., 1995.
Paper 4: Nøst, O.A., On the Outflow of Ice Shelf Water from the Filchner-Ronne and Ross Ice Shelves, Antarctica, Submitted to J Geophys. Res., 1995.
Paper 1
Abstract A simple analytical model has been developed to study the formation of Ice Shelf Water (ISW). ISW is assumed to flow as a buoyancy-driven layer underneath the ice shelf. A relation between potential temperature and salinity in the ISW layer is calculated from the mass and energy balance. This temperature-salinity relation is shown to depend only on the temperature and the salinity of the source water mass and to be practically independent of entrainment and melt rates. The model results are obtained without making any assumptions about entrainment and melt rates. The model is in good agreement with observations under the Ronne Ice Shelf, and it indicates that ISW in the Filchner Depression is formed from Western Shelf Water (WSW) with salinity higher than 34.75 practical salinity units. Such high-salinity water is only observed in the Ronne Depression in the western part of the continental shelf. This implies a circulation of WSW, under the Filchner-Ronne Ice Shelf, from the Ronne Depression into the Filchner Depression. Similarly, the model shows that the ISW observed under J9 at the Ross Ice Shelf has been formed from Low Salinity Shelf Water (LSSW) from the eastern parts of the Ross Sea continental shelf. LSSW must therefore circulate under the eastern parts of the Ross Ice Shelf.
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