UK-OSNAP is leading the way in addressing key issues concerning Subpolar Gyre circulation and fluxes using models, data assimilation and theoretical analysis. There are two strands to the work, led by University of Liverpool and University of Oxford respectively.
In the first component, our aim is to understand how ocean heat storage in the Subpolar Gyre varies. Through a combination of data assimilation and forward model integrations, we plan to identify how changes in the heat storage in the Subpolar Gyre are controlled by a combination of surface heat flux anomalies and the convergence in ocean heat transport. We will also understand how the surface winds and surface buoyancy forcing affect the convergence of heat over the Subpolar Gyre, and explore the connection with the forcing and heat transport at lower latitudes.
In the second component, we will identify the teleconnections between Subpolar Gyre forcing anomalies (surface wind and buoyancy forcing anomalies, and interior buoyancy anomalies including those measured by the OSNAP array) and the strength and structure both of the Subpolar Gyre and of the AMOC at lower latitudes. This will involve a combination of adjoint modelling at non-eddying resolution, high-resolution eddy-permitting forward modelling and theoretical analysis. As well as unravelling the contributions of local and remote wind and buoyancy forcing to the Subpolar Gyre, the AMOC and other climatically relevant metrics such as heat transport, this will aid the design of a longer term monitoring system and the attribution of heat content changes