Exploring density flux variability in the Nordic Seas through new satellite products: Insights from ESA’s Polar Science Cluster ARCTIC-FLOW project

The Atlantic Meridional Overturning Circulation (AMOC) plays a central role in the climate system by transporting and redistributing heat to depth, thereby regulating the effective heat capacity of the ocean under global warming. Observations and projections indicate a potential decline of the AMOC in response to climate change, with far-reaching climate consequences. The Nordic Seas are a key region for the overturning circulation, as dense water formation north of the Greenland–Scotland Ridge feeds the lower limb of the AMOC.

Within this context, the ARCTIC-FLOW project aims to improve our understanding of water mass transformation and overturning processes in the Nordic Seas. The project focuses on identifying the main regions of surface water transformation, quantifying water mass transformation rates, characterizing the temporal and spatial scales of dense water formation, and assessing the impact of extreme freshening events across different subregions of the Nordic Seas.

To support these objectives, we have developed a novel 11-year satellite-based time series of freshwater and density fluxes for the Arctic and sub-Arctic regions. This dataset is derived from the combination of satellite sea surface salinity, sea surface temperature, and surface velocity fields, together with information on mixed layer depth. The satellite products are evaluated and complemented using an extensive set of in situ observations and results from numerical model experiments.

In this contribution, we will present preliminary results on the variability of the newly developed satellite-derived density flux product, highlighting its relevance for studying variability of water-mass transformation processes in the Nordic Seas.