Application of a sea surface roughness formula using joint statistics of significant wave height and spectral wave steepness

Abstract

This article provides some statistical features of the sea surface roughness given as a function of the spectral wave steepness and the significant wave height suggested by Taylor and Yelland (J Phys Oceanogr 31:572–590, 2001), which is best to use for mixed wind sea and swell, and for swell-dominated situations (Drennan et al., J Phys Oceanogr 35:835–848, 2005). Results are obtained using the Myrhaug and Fouques (2008) bivariate statistics of the spectral wave steepness and the significant wave height representing wind sea, swell, and combined wind sea and swell. Associated results are also given for the sea surface drag coefficient and the turbulent energy density, as well as a procedure of estimating the sea surface roughness from 1-, 10- and 100-year contour lines. Finally, a simple example of application is given, demonstrating the effect of the sea surface roughness on slowly varying surge motion of marine structures exposed to wind gust.