Global sea level change signatures observed by GRACE satellite gravimetry

摘要

Ice mass loss on land results in sea level rise, but its rate varies regionally due to gravitational self-attraction effects. Observing regional sea level rates by ocean mass change using the Gravity Recovery and Climate Experiment (GRACE) gravity solutions is difficult due to GRACE’s spatial resolution (~a few hundred km) and other limitations. Here we estimate regional sea level mass change using GRACE data (without contributions from temperature and salinity variations) by addressing these limitations: restoring spatially spread and attenuated signals in post-processed GRACE data; constraining ocean mass distribution to conform to the changing geoid; and judging specific corrections applied to GRACE data including a new geocenter estimate. The estimated global sea level mass trend for 2003–2014 is 2.14 ± 0.12 mm/yr. Regional trends differ considerably among ocean basins, ranging from −0.5 mm/yr in the Arctic to about 2.4 mm/yr in the Indian and South Atlantic Oceans.