Difference analysis of ice sheet mass balance retrieved from various Gravity Recovery and Climate Experiment time-variable gravity field models: a case study in Antarctica and Greenland

Abstract

To analyze the differences in the inversion of Gravity Recovery and Climate Experiment (GRACE) time-variable gravity field models, our study compares the results of ice sheet mass changes from six versions of GRACE monthly gravity field solutions, including the Center for Space Research (CSR) RL06, Jet Propulsion Laboratory (JPL) RL06, German Research Centre for Geoscience (GFZ) RL06, WHU-GPD01s, Tongji-Grace 2018, and HUST-Grace 2020 models, in Antarctica and Greenland. We analyzed the differences of ice sheet mass predicted rates in the temporal, spatial, and spectral domains. In the temporal domain, these differences have a systematic bias among various models and increase over time, especially after 2011. In the spatial domain, the Antarctic ice sheet mass loss rate of WHU-GPD01s is the most consistent with CSR, and the results of GFZ are significantly different than other models (∼15 Gt / year). The Greenland ice sheet mass loss rates of various models are consistent. In the spectral domain, the JPL and CSR models are in great accordance. The differences between the CSR model and the HUST-Grace2020, WHU-GPD01s, and Tongji-Grace2018 models are mainly distributed in the degrees of 20 to 30, 10 to 45, and 25 to 55, respectively. Moreover, the HUST-Grace2020 and CSR models have the smallest spatial discrepancy except for polar regions, and the strip errors for the trend rate of the global equivalent water height are small, which is suitable for research in the mid and low latitudes.