Scientists have discovered a key link between changes in Atlantic Meridional Overturning Circulation (AMOC) strength and subpolar water density at high northern latitudes. Researchers used high-resolution climate modeling to study the connections between midlatitude and subpolar AMOC, finding that density changes in subpolar waters affect subsequent midlatitude AMOC strength.
The study, published in Geophysical Research Letters, suggests that changes in atmospheric pressure impact wind stress and buoyancy at the sea surface, driving variations in water density. These changes propagate southward along the far western side of the North Atlantic, creating a steeper density gradient at midlatitudes and ultimately affecting AMOC strength.
The findings indicate that the Overturning in the Subpolar North Atlantic Program (OSNAP) instrument array data could be used to monitor midlatitude AMOC strength. The study’s results have implications for understanding the ocean’s role in Earth’s climate and inform future ocean-observing systems.
Source: https://phys.org/news/2025-05-density-shifts-rapid-amoc-strength.html