The Arctic-Subarctic Ocean Fluxes (ASOF) program is an international initiative focused on understanding the role of the Arctic and Subarctic oceans in the climate system. The ASOF community concentrates on measuring and modelling the variability of mass, heat, freshwater, and ice fluxes in these high-latitude regions and quantifying key processes governing the variability and connections between the regions. The synthesis of observations, modelling efforts and process understanding are essential to understanding how the Arctic-Subarctic region influences climate variability across the globe, and vice versa.

This year’s ASOF annual workshop, hosted by the Instituto de Ciencias del Mar (ICM) in Barcelona during 13-15 May, 2025, provided a valuable forum to connect the work of EPOC’s Arctic subgroup with the wider Arctic-Subarctic research community. More than 100 scientists from around the world attended in person, with additional participants joining online. Over three days, a wide range of presentations and poster sessions covered research across the Subpolar North Atlantic, the Nordic Seas, the key Arctic gateways, as well as the central Arctic Ocean.

EPOC was well represented throughout the workshop, reflecting the importance of the Arctic as the northernmost extension of the Atlantic Meridional Overturning Circulation (AMOC) — and a region where climate change is progressing nearly four times faster than the global average. Several EPOC researchers presented new results focused on Fram Strait, the main oceanic gateway between the Arctic Ocean and the North Atlantic. Wilken-Jon von Appen (AWI) and Laura de Steur (NPI) shared updates on the inflow and outflow through Fram Strait respectively, using long-term moored observations to provide up-to-date estimates of boundary currents on seasonal to multi-annual timescales. Key findings included a clear warming trend in the West Spitsbergen Current over the past 27 years — with evidence going back to 1969 — impacting the transport of oceanic heat into the Arctic. On the western side of Fram Strait, results showed that the freshwater transport of the East Greenland Current has been declining since 1992 to 2019, however a reversal of that trend occurred in 2020 due to an increase in both freshwater content and southward flow. Overall, the total freshwater transport is by now, dominated by the liquid part and sea ice plays a much smaller role. Increases in the ocean heat transported to the Arctic add to the total Arctic warming, while changes in sea-ice cover and freshwater input can have an imprint on the AMOC.

Till Baumann (IMR) examined the upstream origins of the warm inflow into Fram Strait and the Barents Sea via the Norwegian Atlantic Current (NwAC), using three decades of repeated observations along key transects. The NwAC is a vital branch of the AMOC, transporting heat northward through the Nordic Seas. Till’s research explored the physical drivers behind observed variability and changes in heat transport, offering new insights into the dynamic connection between the Arctic, Fram Strait, and the broader North Atlantic system. Rebecca McPherson (AWI) then presented the downstream impacts of such variability. She identified a new mechanism that drives temperature fluctuations in the West Spitsbergen Current, tracing the advection of these anomalies across Fram Strait to Northeast Greenland’s glaciers. There, ocean heat is shown to directly drive melt rates at the glacier’s grounding line — where the ice meets the ocean bed.

Expanding beyond Fram Strait, Hege-Beate Fredriksen (NPI) presented a status update of the pan-Arctic inverse model effort, which integrates observations from all four major Arctic gateways: Fram Strait, the Barents Sea Opening, Bering Strait, and Davis Strait. Drawing on data from the long-term mooring arrays and hydrographic surveys, this model aims to provide comprehensive estimates of net pan-Arctic heat, freshwater, and volume fluxes and quantify Arctic overturning. Her work is a key step toward closing the Arctic budget and understanding how the region responds to ongoing warming of the global climate.

The next ASOF meeting is planned for Bergen, Norway, in 2026, where the community will continue building on these vital efforts to monitor and model the changing Arctic gateways, and its impacts on the AMOC.