Cross‐Shelf Exchanges Between the East Greenland Shelf and Interior Seas

Abstract

AbstractIncreasing freshwater fluxes from the Greenland ice sheet and the Arctic to the Subpolar North Atlantic could cause a freshening of deep convection regions and affect the overturning circulation. However, freshwater pathways from the Greenland shelf to interior seas and deep convection regions are not fully understood. We investigate exchanges of liquid freshwater between the east Greenland shelf and neighboring seas using drifter data from five deployments carried out at different latitudes along the east Greenland shelf in 2019, 2020, and 2021, as well as satellite data and an atmospheric reanalysis. We compute Ekman transport from winds and geostrophic velocity from satellite altimetry at the shelfbreak and identify the Blosseville Basin and Cape Farewell as areas favorable to cross‐shelf exchanges. We further investigate exchange processes in these regions using drifter data. In the Blosseville Basin, drifters are brought off‐shelf toward the Iceland Sea and into the interior of the Basin. As they are advected downstream, they re‐enter the shelf and are driven toward the coast. At Cape Farewell, the wind appears to be the main driver, although on one occasion we found evidence of an eddy turning drifters away from the shelf. The drifters brought off‐shelf at Cape Farewell mostly continue around Eirik Ridge, where they re‐enter the West Greenland Current. Overall, the identified export over the east Greenland shelf is limited, small scale, and intermittent, thus unlikely to flux large amount of liquid freshwater into the interior, though exchange processes could enhance mixing in the near‐shelf region.