CoAuthors

Benjamin Newcomb (Brown University, USA); Wang Ou (NASA JPL/Caltech, USA)

The melting of the Greenland Ice Sheet results in a weakening of the gravitational pull on the adjacent ocean waters which, in turn, will lead to a relative decrease in sea levels near the ice sheet and an opposite effect of sea level rise in more distant regions. This expected pattern of sea level change associated with recent Greenland Ice Sheet mass loss, hereafter the Greenland Ice Sheet Sea Level Fingerprint (GrIS-SLF), have been calculated using gravity data from the GRACE and GRACE Follow On missions and ice surface elevation data from the ICESat and ICESat-2 missions. While the expected GrIS-SLF patterns are fairly well known, their unambiguous detection has proven to be a challenging task because of the relatively small magnitude of the GrIS-SLF signals relative to natural sea level variability and because the largest predicted GrIS-SLF signals are expected to be found close to the coast (due to the gravitational inverse square law), where traditional nadir altimetry measurements have larger uncertainties. Here we use a combination of satellite altimetry data and an ocean state estimate from the Estimating the Circulation and Climate of the Ocean (ECCO) Consortium to investigate the drivers of sea level change around Greenland and show that the GrIS-SLF fingerprint emerges as the residual between observed and modelled sea level.