Regional Pathways and Impacts of Greenland Ice Sheet Meltwater Simulated in a Sea Ice‒Ocean Model

Abstract

Much attention has been paid to the recent increase in freshwater supply from the Greenland Ice Sheet (GrIS). We conducted numerical experiments using a sea ice–ocean model with a nominal 0.25° resolution to investigate pathways of GrIS meltwater and its effects on the surrounding sea‐ice and ocean fields. We first assessed the simulated sea‐ice and ocean fields against available observations to characterize the model's performance and limitations. Within these limitations, the computationally tractable model configuration enabled 30‐year passive tracer experiments for six regional meltwater sources. The total meltwater tracer shows that GrIS meltwater is concentrated in coastal currents around Greenland and subsequently spreads over Baffin Bay. Consistent with previous studies, the meltwater is transported southward by the Labrador Current and is subsequently advected by the North Atlantic Current to the eastern North Atlantic and eventually to the Arctic Ocean. Regional tracers reveal distinct source‐dependent pathways. Meltwater originating from eastern Greenland is transported through the Labrador Sea and across the North Atlantic, eventually reaching the Barents Sea within 20–30 years, whereas meltwater from western Greenland remains largely confined to Baffin Bay and adjacent waters. Comparisons of numerical experiments with and without GrIS meltwater indicate that the meltwater enhances regional ocean stratification and delays sea‐ice melting in the surrounding areas. GrIS meltwater locally increases the alongshore velocity of coastal surface currents by up to 10%. These results highlight the importance of meltwater source location for its decadal redistribution and clarify the regional ocean and sea‐ice responses to GrIS freshwater input.