Source: AGU Advances
In the coming decades, climate change is likely to lead to a loss of sea ice in and an influx of warmer water to the Arctic Ocean, affecting the ocean’s vertical circulation. Brown et al. recently investigated the forces that drive the Arctic Ocean’s vertical circulation to gain insight into how the circulation might change in the future.
The researchers drew on data from a range of sources, including measurements from shipborne and mooring-based instruments, ERA-Interim, the Arctic Ocean Model Intercomparison Project, and the Polar Science Center Hydrographic Climatology.
Two contrasting factors emerged as the main drivers of vertical circulation as warmer waters flow from the Atlantic Ocean into the Arctic. In the Barents Sea, hitherto the only ice-free part of the Arctic, the ocean loses heat to the atmosphere, causing some of the water to become denser and to sink. Elsewhere, centimeter-sized whirls of turbulence mix in freshwater from rivers and precipitation, resulting in lighter-weight water that remains close to the surface.
As climate change continues to melt sea ice, the balance between these surface fluxes and turbulent mixing is likely to change. More of the ocean surface will be exposed to heat loss to the atmosphere. At the same time, turbulence is likely both to increase and to become more variable. The Arctic Ocean is a source of cold, dense water that feeds the Atlantic Meridional Overturning Circulation, or AMOC, a circulation pattern that holds key influence over the weather in western Europe and North America. Determining how changing circulation patterns in the Arctic Ocean will affect the AMOC should be a focus for future research, the authors suggest. (AGU Advances, https://doi.org/10.1029/2024AV001529, 2025)
—Saima May Sidik (@saimamay.bsky.social), Science Writer
