Oceanic forcing of Helheim Glacier, Greenland: a 5 years synthesis

Wednesday, 17 December 2014: 10:20 AM
Fiammetta Straneo, WHOI, Woods Hole, MA, United States, Dave Sutherland, University of Oregon, Eugene, OR, United States, Gordon S Hamilton, University of Maine, Orono, ME, United States, Leigh A Stearns, University of Kansas, Department of Geology, Lawrence, KS, United States and James Holte, WHOI, Woods Holte, MA, United States
Increased submarine melting at the margins of Greenland’s glaciers is indicated as a potential trigger for their observed acceleration and retreat that began in the late 1990s. Progress on this hypothesis, however, has been hindered by a limited knowledge of the variability of the fjord waters in proximity to the glaciers, and a limited understanding of how such variability may affect submarine melt rates. Here, we present a synthesis of 5 years of oceanic data collected in the vicinity of Helheim Glacier, East Greenland, including the fjord and the nearby continental shelf from moored instrumentation. A comparison of this variability to that of the nearby, larger scale subpolar gyre, obtained from Argo float data, reveal that much of the seasonal and interannual variability observed in the fjord can be attributed to changes in the large scale ocean. The observed fjord variability, in conjunction with the regional atmospheric forcing, is then used to reconstruct changes in submarine melt rates. These, in turn, are compared with observed changes in the characteristics of Helheim Glacier in order to investigate the extent to which submarine melting may be driving glacier variability.