Surface fluxes and streaks in the near-surface layer (Formerly Poster P1.6)

The near-surface region of the atmosphere, including the surface layer and the lower portion of the boundary layer, is a region of high shear. While implicitly assumed to be a region of homogeneous turbulence in estimations of air-sea fluxes, it is in fact usually characterized by strong coherent structures. These structures are transient alternating bands of higher- and lower-speed fluid that roughly align with the mean shear near the surface. The link between the streaks and the spectral variance of the fluxes as a function of height is explored in order to test the theory of Hunt and Carlotti (2001). We also apply quadrant analysis and conditional sampling to investigate the relationship between the streaks and "ejections" and "sweeps" of momentum flux between the atmosphere and the surface. We find that ejections of lower-speed near-surface fluid are the dominant contribution to the surface stress.