Mass balance of the Antarctic Ice Sheet from 2013 to 2018 estimated using the input-output method with updated remote sensing products

The Antarctic Ice Sheet (AIS) has been losing ice mass and contributing to the rise in the global sea-level (GSL) for the last 4 decades, as quantified by using satellite observations. We developed a framework for implementing the state-of-the-art input-output (IO) method that has the advantage of explicit estimation of the mass balance of individual glaciers, basins and the continent. We estimated the mass balance of the AIS from 2013 to 2018 using improved observations and updated datasets recently made available, including annual ice flow velocity maps from the Inter-mission Time Series of Land Ice Velocity and Elevation (ITS_LIVE) dataset, the BedMachine and the Princess Elizabeth Land (PEL) Earth System Science Data (ESSD) datasets, and the surface mass balance from the RACMO 2.3 system. For example, using the improved ice thickness data, the proposed method for ice discharge estimation enables a 10% reduction of uncertainty in ice discharge. During the period of 2013-2018, an ice discharge acceleration of 6.9 & PLUSMN;6.5 Gt yr(-2) in West Antarctica (WA) was detected, which contributed significantly to the estimated mass loss of & SIM;1069 Gt (-178.2 & PLUSMN;108.9 Gt yr(-1)) in the AIS. On the other hand, Queen Maud Land, East Antarctica (EA), showed clearly a mass gain rate of 56.0 & PLUSMN;10.0 Gt yr(-1) due to the regional increase in surface mass balance. Our results extended the estimation period by 3 years in comparison to the published study using the same annual velocity maps from the ITS_LIVE dataset. Furthermore, our results, along with those from other studies using the IO method, reassures the acceleration of recent mass loss in WA and Wilkes Land in EA, which are caused by glacier thinning and ice shelf basal melting. Compared with the long-term mass balance record since 1979, our results suggest that the mass loss in AIS accelerated in the last decade. The developed framework can be modified for mass balance estimation of the AIS or for other ice sheets by using velocity maps from other satellite data or from different periods.

Automated summary

Using satellite observations, we developed a new method to estimate the mass balance of the Antarctic Ice Sheet. Our findings show that the ice sheet has been losing mass for the past 4 decades, contributing to the rise in global sea level. We estimated the mass balance from 2013 to 2018 and observed an accelerated ice loss in West Antarctica and a mass gain in East Antarctica.