A coupled wind-internal wave system

Abstract

This paper presents the results of an experimental study of ocean internal waves observed by coastal and airborne radars. The radar modulation of a number of internal waves, as evidenced by slicks, is thought to vary as does the wind direction. A boundary-layer transition study was applied for the explanation of radar signals in X-, K/sub u/-, and K/sub a/-bands from the ocean disturbed by internal waves. The study was motivated both by the need to find different wind regimes above a slick smoothed by a current from an internal wave and rough seas around the slick. The most significant results show a strong coupling the transition zone slick-free sea surface and a high backscattered signal at the HH-polarized image downstream. There is no comprehensive theory for explaining of the internal-wave radar clutter in all environmental conditions. Backward radio-wave scattering by rough seas at low grazing angles has a number of peculiarities. Field studies disclose that the specific effective scattering value is a function of grazing angle, radio wavelength, signal polarization, sea state, and internal-wave aspect relative to the wind direction and a number of other parameters. In this paper the author presents an aerodynamical model allowing the high modulation of an observable radar cross section from the internal waves in X- and K-bands tobe validated.