Alongshore winds force warm Atlantic Water toward Helheim Glacier in
southeast Greenland
Abstract
Enhanced transport of warm subsurface Atlantic Waters (AW) into
Greenland fjords has driven glacier mass loss, but the mechanisms
transporting AW to the fjords remain poorly characterized. Here, we
identify a wind-driver for AW inflow toward Sermilik Fjord abutting
Helheim Glacier, one of Greenland’s largest glaciers. Often associated
with the passing of cyclones and subsequent sea surface lowering, a
weakening or reversal of northeasterly alongshore winds stimulates
coastal ocean upwelling that, through interactions with Sermilik’s
bathymetric trough on the continental shelf, leads to enhanced AW
upwelling and inflow along the trough. These intrusions produce ocean
warming at deep moorings near Sermilik Fjord mouth (0.31±0.18°C) and
within the fjord (250m: 0.30±0.19°C; 350m: 0.17±0.09°C) that is not
diminished by subsequent coastal downwelling. Similar wind-driven
processes at other bathymetric trough regions around Greenland may play
a substantial role in ocean heat transport towards much of the Greenland
Ice Sheet.