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Ice Shelf Basal Melt and Influence on Dense Water Outflow in the Southern Weddell Sea
Author(s) -
Akhoudas Camille,
Sallée JeanBaptiste,
Reverdin Gilles,
Aloisi Giovanni,
Benetti Marion,
Vignes Lucie,
Gelado Maria
Publication year - 2020
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2019jc015710
Subject(s) - ice shelf , geology , oceanography , sea ice , continental shelf , fast ice , shelf ice , iceberg , antarctic sea ice , melt pond , weddell sea bottom water , circumpolar deep water , antarctic bottom water , water mass , arctic ice pack , cryosphere , north atlantic deep water , deep water
We use new observations of stable water isotopes from a research cruise in early 2017 to highlight ocean‐ice interactions occurring under Filchner‐Ronne Ice Shelf, the largest Antarctic ice shelf. In particular, we investigate the properties of Ice Shelf Water with temperature lower than the surface freezing point, in the Filchner Depression. We identify two main flavors of Ice Shelf Water emerging from beneath the Filchner Ice Shelf, which originate from High Salinity Shelf Water end members with distinct characteristics. Furthermore, these two High Salinity Shelf Water end members interact with areas of the ice shelves with different basal properties to produce different versions of Ice Shelf Water. These water masses are associated with different rates of basal melting and refreezing, which we quantify. Ice Shelf Water types that flow out of the ice shelf cavity are composed of 0.4% of mass from ice shelf (melt minus freeze) when sampled at the front of Filchner Ice Shelf. The slightly lighter Ice Shelf Water version mixes directly with ambient water masses as it flows northward on the continental shelf. The resulting Ice Shelf Water mixture with temperature below the surface freezing point ultimately sinks along the continental slope into the deep ocean, as a precursor of the Weddell Sea bottom waters.