The observed increase of freshwater storage in the western Arctic Ocean over the past few decades has coincided with favourable changes in wind patterns, reports a study published online this week in Nature Geoscience. If the accumulation of freshwater has been wind-driven, a reversal of the wind patterns could release the freshwater, with potential implications for the regional ocean circulation. Katherine Giles and co-authors found an increasingly steep dome of water in the western Arctic in satellite measurements of sea surface height between 1995 and 2010, and a corresponding change in wind patterns. The dome is associated with the Beaufort Gyre, a circular current in the western Arctic Ocean, and its steepening suggests an acceleration of the gyre. The researchers estimate that about 8,000 cubic kilometres of freshwater is stored in the Beaufort Gyre through this acceleration, in agreement with hydrographic measurements.