Critical role for mesoscale eddy diffusion in supplying oxygen to hypoxic ocean waters

Estimates of the oceanic lateral eddy diffusion coefficient A(redi) vary by more than an order of magnitude, ranging from less than a few hundred m(2)/s to thousands of m(2)/s. This uncertainty has first-order implications for the intensity of oceanic hypoxia, which is poorly simulated by the current generation of Earth System Models. Using satellite-based estimate of oxygen consumption in hypoxic waters to estimate the required diffusion coefficient for these waters gives a value of order 1000 m(2)/s. Varying A(redi) across a suite of Earth System Models yields a broadly consistent result given a thermocline diapycnal diffusion coefficient of 1 x 10(-5) m(2)/s.