CoAuthors

Steve Nerem (Colorado Center for Astrodynamics Research , USA)

Net mass loss of the Greenland Ice Sheet is significantly contributing to global sea level rise. Some of Greenland’s net ice loss is due to melting of its marine-terminating glaciers due to warming ocean waters. Oceanographic observations in the ocean basins of the northwest North Atlantic show large decadal variations of ocean temperature and salinity in the upper 2000 m. Waters in these basins transitioned to a warming phase in the late 1990s and for more than a decade thereafter many of Greenland’s glaciers were observed to retreat, accelerate, and thin. Linking the observed glacier changes to ocean warming remains challenging because very few in situ ocean observation exist on the shallow continental shelf between the ice sheet and the offshore ocean basins. Here, we report on progress using satellite altimetry to infer thermosteric variations on the continental shelf during this time period. Our project uses remote sensing and in-situ data, including satellite altimetry, numerical modelling, and data assimilation to characterize and reconstruct the ocean state in this region over the past 25 years. This three-dimensional time-varying reconstruction of the ocean state will allow us to determine (1) how have ocean temperatures immediately adjacent to the ice sheet changed and (2) the extent to which satellite altimetry can be used to infer ocean temperature changes in the region. This work will 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