Dependence of drag coefficient on the directional spreading of ocean waves

Abstract

Drag coefficient C10 is one of the main characteristics used for calculation of surface stress based on mean wind speed U10. Most of the dependences employ the sea drag as a function of this wind speed. It has been proposed, however, that for a given wind speed C10 can depend on a number of other properties in the air‐sea system. In the present paper, dependence of the drag coefficient on the directional spreading of surface waves is studied numerically. It is shown that such dependence can be significant. For a given wind speed, the sea drag can grow as much as 25% depending on the width of directional spectrum. The highest drag corresponds to the narrowest spectra, and for very narrow directional distribution it saturates. The largest impact of the sea‐drag directional dependence is observed for the highest winds. Accounting for the directional spread of surface waves is therefore essential to improve parameterizations of C10.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jun 08, 2012
Source ID
10.1029/2012jc007920

Entities

People

  • Alexander V. Babanin
  • Chia‐huan Ting
  • Dmitry Chalikov
  • Tai‐wen Hsu

Organizations

  • Australian Research Council
  • Office of Naval Research

Tags

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Microwave Engineering.
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers