The 13th Symposium on Boundary Layers and Turbulence

P2B.7
NEAR SUBSURFACE SHEAR AND DISSIPATION OBSERVATIONS IN THE COASTAL OCEAN

Wade R. McGillis, Woods Hole, MA; and E. J. Bock, J. B. Edson, N. M. Frew, and T. Hara

The atmospheric-ocean interface, one of the most dynamic parts of the ocean, is also one of the most difficult to study. Ships pitch through the interface with too much amplitude and unpredictability, while stationary platforms move too little, for investigating processes at the moving surface. Near surface turbulence and thereby the transfer of energy and momentum between the ocean and atmosphere are significantly modified by the presence of surface waves and surface films. Despite many past experimental and theoretical studies, we have not been able to satisfactorily explain this wind-wave coupling mechanism. As part of our comprehensive study of interfacial hydrodynamic processes, the mobile wave-following research catamaran Ladas was deployed during both the Coastal Ocean Processes/Marine Boundary Layer experiment 1995 (CoOP 95/MBL II) and the Coastal Ocean Processes experiment 1997 (CoOP 97). In situ detection and mapping of subsurface shear and turbulent dissipation was performed. During CoOP 95/MBL II, both an Acoustic Doppler Velocimeter (ADV) and a hot-film anemometer were deployed simultaneously at a mean depth of 30 cm. During CoOP 97, an array of six ADVs were deployed from 25 cm to 150 cm below the mean water surface. These observations provide some new insights into the coupling between near subsurface velocity structures, atmospheric forcing, short wind-waves, and surface films

The 13th Symposium on Boundary Layers and Turbulence