While transient mesoscale motions are stochastically somewhat weaker over the sea than over the land, their impact may be greater. Unlike over land, the surface roughness responds to transient variations of the wind leading to a nonlinear influence on the surface stress. While "background" mesoscale motions are most important with weak large-scale flow, they appear to influence the surface stress for stronger wind speeds as well. These tendencies are documented using data collected during the CBLAST Weak Wind Experiment and a pilot experiment using the CIRPAS Twin Otter off of the coast of Monterey in April 2008.

The influence of different mesoscales on the surface stress are examined by decomposing the airflow into a multiresolution decomposition. We also attempt to partially isolate the influences of mesoscale variations of wind and the influence of SST. Results are interpreted in terms of the bulk aerodynamic formulation.