Accelerated ice-sheet mass loss in antarctica from 18-year satellite laser ranging measurements

Abstract

Accurate estimation of the ice-sheet mass balance in Antarctic is very difficult due to complex ice sheet condition and sparse in-situ measurements. In this paper, the low-degree gravity field coefficients of up to degree and order 5 derived from Satellite Laser Ranging (SLR) measurements are the first used to determine the ice mass variations in Antarctica for the period 1993-2011, which are compared to Gravity Recovery and Climate Experiment (GRACE). Results show that the ice mass is is decreasing at the rate of −36±13 Gt/y in Antarctica, −42±11 Gt/y in West Antarctica and increasing at 6±10 Gt/y in East Antarctica from 1993 to 2011. The ice mass variations from the SLR 5×5 have a good agreement with the GRACE 5×5, GRACE 5×5 (1&2) and GRACE (60×60) for the entire continent since 2003, but SLR solution of 5×5 is not sufficient to quantify ice losses in West and East Antarctica, respectively. The rate of ice loss in Antarctica is −28±17 Gt/y for 1993-2002 and −55±17 Gt/y for 2003-2011 within one sigma, indicating significant accelerated ice mass losses since 2003. Furthermore, the results from SLR are comparable with GRACE measurements.