9819066 The PIs hypothesize that an abyssal gyre fills the western basin of the North Atlantic from the Equator to near 300 N, with the strongest recirculation located in the tropical Guiana Basin. To date, measurements of the deep western boundary current portion of that flow show it to be so large as to upset the overall balance of the meridional overturning circulation. The hypothesized gyre is one mechanism, which, if shown to be of sufficient magnitude, would account for this discrepancy. It has never been observed directly, and the PIs propose a field experiment to to so. The study would focus on the narrow Guiana Basin between 80 N and 150 N. Current meters and temperature sensors, supported by shipboard hydrography and ADCP measurements would be arrayed so as to directly determine the northward flow in this gyre.
