Complex Patterns of Antarctic Ice Sheet Mass Change Resolved by Time‐Dependent Rate Modeling of GRACE and GRACE Follow‐On Observations
Lei Wang, J. L. Davis, Ian M. Howat
Abstract
Abstract The Antarctic Ice Sheet (AIS) is a major contributor to current global sea‐level change and the largest potential source of future sea‐level change. Variability in AIS mass balance on a wide range of spatiotemporal scales obscures secular trends, increasing the uncertainty of projections. We introduce a novel approach for analyzing satellite gravity observations to estimate time‐varying mass‐change rates and resolve the time scales and amplitudes of rate fluctuations. The new analysis resolves a higher degree of variability than expected over all AIS sectors. Quantifying rate fluctuations on a range of time scales, we demonstrate that loss from the West AIS is characterized by a multidecadal trend, whereas variations of the East AIS are dominated by substantial, short‐term accumulation changes that impact AIS mass balance as whole. These complex spatiotemporal variabilities highlight the need to include stochastic processes in estimates of loss rates.