Towards Estimating High-Resolution Ice Mass Changes from GRACE-FO Range Measurements

Recovering ice mass changes at higher spatial and temporal resolution from GRACE-FO remains challenging when using conventional monthly gravity field solutions. We investigate the capability of GRACE-FO inter-satellite ranging (LRI) observations to resolve ice mass variability. Using the LRI measurements on board GRACE-FO to look at gravity anomalies in the line-of-sight direction is an emerging method for observing large mass changes on sub-monthly timescales. We evaluate the potential of this line-of-sight gravity information to study ice mass change, where signals are dominated by long-term trends and ice stream surges are typically smaller in amplitude than hydrological variations. Using tailored regularisation and complementary altimetry data, we are trying to find and push the limits of GRACE-FO line-of-sight gravity. In this study, we are using Greenland and Iceland during the summer periods of 2019-2022 as a test case to look at both the limits in spatial and temporal resolution.