Quantifying Dynamical Proxy Potential through Oceanic Teleconnections in the North Atlantic

Oceanic quantities of interest (QoIs), e.g., ocean heat content or transports, are often inaccessible to direct observation, due to the high cost of instrument deployment and logistical challenges. Therefore, oceanographers seek proxies for undersampled, unobserved, or unobservable QoIs. Conventionally, proxy potential is assessed via statistical correlations, which measure covariability without establishing causality. This paper introduces an alternative method: assessing dynamical proxy potential. Using an adjoint model, this method unambigiously identifies the physical origins of covariability. A North Atlantic case study illustrates our method, within the ECCO (Estimating the Circulation and Climate of the Ocean) state estimate. We find that wind forcing along the eastern and northern boundaries of the Atlantic drives a basin-wide response in North Atlantic circulation and temperature. Due to these large-scale teleconnections, a single subsurface temperature observation in the Irminger Sea informs hea...