New production stimulated by high-frequency winds in a turbulent mesoscale eddy field

Abstract

Using an idealized model of an oligotrophic open-ocean region characterized by intense sub-mesoscale turbulence, we show that the presence of energetic near-inertial motions, forced by high-frequency winds, triggers transient nutrient inputs in the surface mixed-layer, stimulating new production. We also show that this production increase is larger than the increase due to the Ekman transport resulting from a slow-evolving wind forcing. The nutrient supplies are due to the interaction between near-inertial motions and the sub-mesoscale frontogenetic dynamics that reinforces both the vertical advection and vertical diffusion, especially within sub-mesoscales features. The net result is an uplift of new production from the subsurface to the mixed-layer. A direct consequence is that the sub-mesoscale filamentary patterns of phytoplankton should become much more observable from space in the presence of high-frequency winds. Copyright 2009 by the American Geophysical Union.