Effects of mesoscale eddy/wind interactions on biological new production and eddy kinetic energy

Abstract

Accounting for ocean currents in the bulk parameterization of the wind stress might represent a physically more plausible way to force an ocean model than ignoring their effect. We show in this study that using the air-sea velocity difference instead of the atmospheric wind in the wind stress formulation dampens both the near-surface eddy activity and the biotic carbon assimilation in a high-resolution model of the North Atlantic. The former is significant, corresponding to a reduction down to 50% in the tropical Atlantic, while in higher latitudes (in agreement with previous results) the reduction of eddy activity is only around 10%. The effect on biotically mediated new production and air-sea carbon fluxes is, on the other hand, minor. New production is reduced by less than 5% on a basin average, while simulated air-sea CO2 fluxes are barely affected at all. The model results imply that eddy/wind interaction introduced by accounting for ocean currents in the wind stress formulation does not drive any additional (and hitherto unaccounted) nutrient fluxes to the sunlit surface of the subtropical gyre, as was recently proposed in the literature. Copyright 2009 by the American Geophysical Union.