The Balance and Abnormal Increase of Global Ocean Mass Change From Land Using GRACE

Abstract

Global ocean mass (GOM) change, which is mainly influenced by water outflow from land, has been identified as one of the important contributors to present-day sea level rise. Here, we delineated GOM change by dividing the land into five parts, which are exorheic river basins, endorheic basins, polar ice sheets, and land glaciers and ice caps, by the Gravity Recovery and Climate Experiment mass concentration solutions, 2002–2017. We estimated their total contribution to GOM change to be 568.92 ± 21.43 GT•yr−1, which is statistically congruent with the Gravity Recovery and Climate Experiment estimated GOM change (579.46 ± 46.62 GT•yr−1). The melting of Earth's ice reservoirs is the dominant contribution in the whole period. However, an abnormal increase is found in the trend of GOM change with an amplitude of approximately 100% since August 2008. Further finding reveals that melting of Antarctica Ice Sheets are increasing fast and significantly dominates among other geophysical contributions to the abnormal increase at 34.28%, following with the water storage change of exorheic river basins at 28.71% and the melting of Greenland Ice Sheets at 22.76%, which is postulated to be resulting from intensified ice wastages and precipitation during the last decade.