抄録
We examined field observation data of the friction velocity on the sea surface to describe the roughness and the drag coefficient in terms of windsea parameters. Estimations of the friction velocity were made by the combined use of the eddy correlation and inertial dissipation methods. Based on directional wave spectra, we extracted only pure windsea data to carry out the parameterizations for ideal wave-fields. The sea-surface roughness was parameterized in terms of two dimensionless windsea parameters, i.e., the wave-wind coefficient and the windsea Keulegan number. The drag coefficient was formulated empirically on the basis of the result of the roughness parameterization. The validity of the empirical expression for the drag coefficient was confirmed in comparison with the field observation data.
