Aircraft estimates of the geostrophic drag coefficient and the rossby similarity functions A and B over the sea

• Published in: Boundary-layer meteorology Vol. 39; no. 3; pp. 219 - 231
• Main Authors: Grant, A. L. M., Whiteford, R.
• Format: Journal Article
• Language: English
• Published: 01-05-1987
• Subjects: Oceans, Seas, and Interconnections
• ISSN: 0006-8314; 1573-1472
• DOI: 10.1007/BF00116119

Estimates of the geostrophic drag coefficient and the Rossby similarity functions A and B, obtained from data collected by an instrumented aircraft over the sea, are presented. The average value of the geostrophic drag coefficient is 0.027 and is independent of the geostrophic wind speed. The dependence of the similarity functions A and B upon boundary layer parameters is investigated. The function A is found to depend upon baroclinicity parameters, while B depends upon the parameter u*/fh (where u* is the surface friction velocity, f is the Coriolis parameter, and h is the boundary layer depth). By using the geostrophic drag coefficient found here and the results of surface drag coefficient studies, a relationship between geostrophic and surface wind speed is obtained which agrees well with empirical data.