Greenland Meltwater in the Coastal Current System of Southern Greenland

Nicholas Beaird, Rutgers University, New Brunswick, NJ, United States, Fiammetta Straneo, Scripps Institution of Oceanography, La Jolla, CA, United States, Isabela Alexander-Astiz Le Bras, Woods Hole Oceanographic Inst, Woods Hole, MA, United States, Robert S Pickart, Woods Hole Oceanographic Institution, Woods Hole, MA, United States and William J Jenkins, WHOI, Woods Hole, MA, United States
Abstract:
The Greenland Ice Sheet is losing mass at an accelerating pace, increasing its contribution to the freshwater budget of the subpolar North Atlantic. This meltwater may influence regional water mass formation/transformation and have gyre-scale impacts, but the links are complex and poorly observed. Here we report on noble gas-derived observations of glacial meltwater distributions and fluxes in the East/West Greenland Current System on 16 cross-shelf sections around Cape Farewell. Noble gases provide a quantitative evaluation of meltwater concentrations that is not possible with standard hydrographic observations alone. These data, obtained in the summer of 2016, are in the vicinity of the East and West mooring lines of the Overturning in the Subpolar North Atlantic Program (OSNAP). As would be expected, meltwater concentrations are low relative to previous measurements taken inside glacial fjords, but are slightly higher than the only previous observations from this area. Meltwater concentrations are highest close to shore in the East Greenland Coastal Current, but extend to the shelfbreak where some meltwater is carried in the combined East Greenland/Irminger Current. The distribution of meltwater becomes less concentrated at the coast as the East Greenland Coastal Current rounds Cape Farewell. Meltwater transport estimates are reported in the context of the OSNAP moored records of the seasonally varying freshwater transport, and also compared to previous synoptic shipboard surveys in the region.