Turbulent dissipation on the margins of the South China Sea

Abstract

Measurements of turbulence along the continental slope, shelfbreak, and shelf of the northern South China Sea are presented from a 10-day measurement program during April 2005. The shelfbreak region was characterized by a deep stratification that appears to be typical of the late winter-monsoon. This appears to shift the wave field at the shelfbreak from the soliton-like depression anomalies observed in previous years to a more complex wave field, supporting high-frequency waves in both upper and lower depth-intervals of the water column. On average, 30% of the depth-integrated turbulent dissipation occurs within 10 m of the bottom, where baroclinic energy is preferentially dissipated. Dissipation levels, reaching 50 mW/m2, are an order of magnitude larger than those attainable through frictional dissipation of the local barotropic tide, and an order of magnitude larger than levels typical in the open ocean. Copyright 2008 by the American Geophysical Union.