SUPERFLOW will determine the pathways and dynamics of the flow of the densest water in the Nordic Seas that is the main source to the lower limb of the Atlantic Meridional Overturning Circulation (AMOC), a critical component of the global climate system. Warm and saline Atlantic Water flowing northward across the Greenland-Scotland Ridge releases heat to the atmosphere and helps maintain the temperate climate of northwest Europe. The resulting cold, dense water returns southward at depth as overflow plumes through gaps across the ridge. The densest water supplying the two major overflow passages located east and west of Iceland has the same source, and while the exchange flows across the Greenland-Scotland Ridge have been monitored for several decades, the circulation and partitioning of the upstream flows that are co-located northeast of Iceland are not yet quantified and understood. Using unpublished, 2-year long observational time series of temperature, salinity, and velocity, the mean properties, structure, and volume transport of the dense water currents on the slope northeast of Iceland will be determined. A high-resolution, realistic simulation from an ocean general circulation model will be used to identify the sources and pathways of the dense water, while an idealised isopycnal model will be employed to understand the dynamics of the two currents supplying the overflows to either side of Iceland. The combination of observations and numerical simulations in a region whose importance only recently has been recognised will provide novel insights into the upstream characteristics of the dense-water pathways supplying the two deepest passages through the Greenland-Scotland Ridge and thus the lower limb of the AMOC. Advancing this understanding is imperative for an accurate prediction of how the AMOC will respond to a changing climate.
MSCA-TOPP-UT-Toppfinansiering av MSCA utgående kandidater