Linking Sea Surface Height Variations with Hydrographic Variability around the Greenland Ice Sheet to Improve Understanding of Sea Level Rise
- (Jet Propulsion Laboratory)
The acceleration of global mean sea level rise in the past several decades has been driven, in part, by increased melting of the Greenland Ice Sheet. Over the satellite altimetry period, the rate of global mean sea level rise has nearly doubled relative to its 20th century average to 3.2 mm/yr, with ~0.75 mm/yr now attributable to the net transfer of water mass from the melting of Greenland’s grounded ice. One hypothesis for the increase in ice sheet mass loss is that the subsurface waters circulating above its continental shelf have warmed, leading to increased submarine melt rates at the ice-ocean interface of its marine-terminating glaciers. While in situ temperature and satellite sea surface height (SSH) data in the basins adjacent to the ice sheet indicate warming over the past two decades, few hydrographic data exist on the shelf to test the hypothesis. Our goal is an improved understanding of sea surface height and ocean heat variability on the Greenland shelf, its relationship to hydrographic and atmospheric variability, and the implications for past and future ocean-ice sheet interaction and sea level rise through the development of new techniques to analyze satellite ocean surface topography data.
To this end, we will investigate the past two and half decades of sea surface height and ocean heat content on Greenland’s shelf using remote sensing data including altimetry, atmospheric reanalyses, in situ hydrography data, and numerical ocean modelling. We propose the following activities:
By combining our ocean heat content reconstructions with ice sheet measurements from OMG and other NASA missions, including ICESat-1, Operation Ice Bridge, and the forthcoming ICESat-2, we will be able to link changes of Greenland’s marine-terminating glaciers to ocean temperature changes on their neighboring shelves. Our study will also pave the way for future monitoring of ocean thermal forcing of the Greenland Ice Sheet using altimetric data from the upcoming SWOT, Sentinel-3, and Jason-CS missions.