Subtleties in forcing eddy resolving ocean models with satellite wind data

Abstract

Using new global satellite remote sensing data, we show that ignoring the ocean current dependence in the wind stress artificially increases global wind power input to the oceanic general circulation by about 32%, and more than doubles the input in the regions of strong ocean current systems. Scatterometer-derived wind stress naturally accounts for the moving ocean that is not included in traditional wind stress products. However, forcing an ocean model with a scatterometer-derived wind stress cannot actually account for the ocean current effect on the wind power input. The difference between the real and modeled surface eddy fields can reduce the damping associated with the ocean current dependence in wind stress, leading to a positive bias in global wind power input of about 23%. Most of this spurious energy flux goes directly to the fluctuation eddy field and is several times larger than the energy flux to real ocean eddies.