Table 1. Abbreviations Used in Text Abbreviation Full Name Description AABW Antarctic Bottom Water bottom water originating from Antarctica, traceable to 40degreeN ACC Antarctic Circumpolar Current ocean current system that circumnavigates the Antarctic Continent ASW Antarctic Surface Water surface water around Antarctica that interacts directly with the atmosphere CDW Circumpolar Deep Water intermediate water mass of ACC ESW Eastern Shelf Water product of CDW and meltwater from the eastern Weddell ice shelves FRIS Filchner-Ronne Ice Shelf largest ice shelf in Weddell Sea, largest ice shelf (by volume) in Antarctica GNAIW Glacial North Atlantic Intermediate Water northern source intermediate water that existed during the LGM - corresponds roughly to modern NADW, but existed at shallower depths with modified properties GSSBW Glacial Southern Source Bottom Water southern source bottom water that existed during the LGM HSSW High Salinity Shelf Water water formed on continental shelves of Antarctica through sea ice formation, S > 34.5 ISW Ice Shelf Water water formed in sub-ice shelf cavities - defined as water with potential temperature lower than the surface freezing point (<ap -1.9degreeC) LGM Last Glacial Maximum time period corresponding to most recent relative maximum of continental ice sheet size, ap20,000 years before present MWDW Modified Warm Deep Water transition water mass between WW and WDW, likely source of continental shelf water masses NADW North Atlantic Deep Water water mass that originates from North Atlantic, identifiable in global ocean data sets as a deep salinity maximum WDW Warm Deep Water modified form of CDW found in Weddell Sea identified by temperature and salinity maximum around 300-600 m WSDW Weddell Sea Deep Water water in Weddell Sea that lies above WSBW and outflows to become AABW WSBW Weddell Sea Bottom Water deepest water mass in Weddell Sea, densest and coldest water mass around Antarctica, contributes eventually to AABW after mixing upward to become WSDW WW Winter Water water mass defining winter mixed layer of Weddell Sea, formed from underlying WDW and brine rejection