Crossroads - Deployment 1 of 2

Crossroads is a Lagrangian field program combined with numerical modeling aimed at describing the processes that break or maintain connectivity of the lower limb of the Atlantic Meridional Overturning Circulation (AMOC). Crossroads will be embedded in highly complementary field projects by Canadian and European researchers with the same fundamental question regarding connectivity. Specific objective is to determine the processes governing the deep circulation along the western boundary between the subpolar and subtropical North Atlantic—the so-called "transition zone" (TZ), thought to be critical to the latitudinal coherence of the AMOC. We will directly observe the interaction between the deepest layers of the Deep Western Boundary Current (DWBC) with the North Atlantic Current through the TZ by releasing acoustically tracked RAFOS floats in the DWBC east of the Grand Banks at 2500-3800-m depth and track them for two years as they drift through the TZ. The field program is embedded in a complementary hydrographic, Eulerian and modeling investigation also focused on the connectivity of the DWBC through the TZ funded by the EU "Explaining and Predicting Overturning Circulation" (EPOC) and French "Crossroads" programs, which will be leveraged scientifically and logistically.