TO THE NORTH WITH THE GULF STREAM: OCEAN DYNAMICS AROUND ICELAND
Iceland is a crossroad for the Atlantic Meridional Overturning Circulation (AMOC), with surface Atlantic warmer travelling North and deep-water mass formed in the (sub-)Arctic Ocean overflowing into the North Atlantic. The pathway of the currents carrying the bottom water masses is still under debate due to a lack of observations. Using state-of-the-art numerical simulation, we first present in detail the pathway of the bottom currents in the specific area South of Iceland; secondly, we unveil the importance of mesoscale activity for the dynamics and the local stratification using novel SWOT satellite altimetry. Moreover, the steadily warming surface waters of the northeastern Atlantic over the recent decades use vertical eddy fluxes as pathways to the deeper layers suggesting that warming of the lower limb of the AMOC may be occurring at hotspots such as the Iceland-Faroe Ridge. These results have strong implications for the local biodiversity, to maintain benthic species and trigger spring phytoplankton blooms.