A strengthening dipole pattern in Arctic Ocean dynamics observed by GRACE/GRACE-FO

The Arctic Ocean has changed rapidly over recent decades as sea ice has declined, freshwater inputs have increased, and atmosphere–ocean coupling has evolved. Yet the resulting basin-scale variability in ocean mass remains poorly constrained because in situ observations are sparse and satellite altimetry is limited at high latitudes. Here we use satellite gravimetry from GRACE and GRACE-FO to quantify Arctic Ocean bottom pressure (OBP) variability from 2002 to 2024, providing a direct measure of mass redistribution that is independent of steric effects. To isolate dynamic ocean signals, we remove land leakage and eustatic contributions using a forward-modeling framework that accounts for self-attraction and loading. Empirical Orthogonal Functions (EOF) analysis of the residual OBP field reveals a leading-mode dipole pattern, with increasing ocean mass in the Beaufort Gyre region within the Canadian Basin and decreasing mass in the Kara Sea and Barents Sea. The corresponding principal component shows a robust strengthening over the two-decade record. While the underlying physical mechanisms warrant further investigation, the overall dipole structure is consistent with recent modeling studies suggesting intensified surface circulation under continued sea-ice loss. Overall, GRACE-derived ocean mass captures coherent, multi-decadal Arctic circulation change in a warming climate.