Tracking a key AMOC pathway: how Atlantic water is transformed before reaching the Arctic

The Atlantic inflow across the Iceland–Faroe Ridge carries almost half of the warm Atlantic water entering the Nordic Seas and Arctic Ocean, making it a key component of the climate system and the Atlantic Meridional Overturning Circulation (AMOC).

In a new study supported by ObsSea4Clim, researchers investigate how this water mass changes on its journey towards and across the ridge – a subsea topographic barrier. Using satellite altimetry and drifter observations, they show that Atlantic water is significantly cooled and freshened before and during its crossing, primarily through mixing with Arctic water masses. 🛰️🛟🔍

The study further finds that:
🔹Variability in the Subpolar Gyre strongly influences the pathway, temperature and salinity of the Atlantic inflow
🔹The freshening of the Atlantic water crossing the ridge reduces the salinity contrast needed for dense-water formation at high latitudes by 20–30%
🔹Volume transport of Atlantic Water increased by 12 ± 7% and the heat carried towards the Arctic by 16 ± 8% between 1993 and 2023

Improving our understanding of these processes is essential for strengthening ocean and climate models, enhancing climate predictions, and supporting evidence-based adaptation and mitigation strategies.

📖 Read the full article: https://doi.org/10.5194/os-22-2405-2026

Cite as: Eriksdóttir, G., Hansen, B., Larsen, K. M. H., Olsen, S. M., Gierisch, A. M. U., and Ólafsdóttir, S. R.: Water mass modification of the warm Atlantic Inflow towards the Arctic across the Iceland-Faroe Ridge, Ocean Sci., 22, 2405–2423, https://doi.org/10.5194/os-22-2405-2026, 2026.