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The effects of nonlocal connection between an internal wave field and centimeter-and decimeter-scale waves were studied using the JUSREX-92 data. Centimeter-scale wave parameters were measured by means of a ship-mounted, X-band side-looking radar, decimeter-scale wave parameters were measured with a two-dimensional optical device (the wave spectrum analyzer) and parameters of the internal waves were measured by a towed, profiling batfish operated by the Atlantic Division of the Shirshov Institute of Oceanology. We will show that disturbed regions of centimeter-and decimeter-scale surface waves exist at distances up to 1 km away from the region of internal waves. The spatial period of the surface wave spectral density variations can differ from the internal wave length, but the magnitude of this difference depends on the relative direction of surface wave propagation. These variations in the spectral density of decimeterscale surface waves can be explained in terms of a standard kinematic model of the action of internal waves on wind waves. The variations in the spectral density of centimeter waves is a result of a cascade mechanism: the surface flow caused by the internal waves transforms the decimeter-scale waves, which then cause the centimeter-scale wave variations.It is the most widespread opinion, that surface manifestations of internal waves (IW) look like strips along the internal wave crests having the IW spatial period and propagating with the velocity equal to the IW phase velocity. However, it was obtained, during the expedition on the scientific-research vessel "Vityaz" in 1982 that in the decimeter wavelengths of the surface waves structure of manifestation of short internal wave trains on the sea surface is more complicated (Basovich,l986). In particular, the following peculiarities were registered: the scale of variation in the spectral density of the surface waves smaller than the internal wave period, existence of a forerunner of surface anomalies, the variation in the intensity of the wind waves anomalies along the internal wave trains. Later, these effects were registered at centimeter wavelengths as well (Basovich,l988). In this paper, some peculiarities, which were obtained during the JUSREX-92 field experiment, of such unlocal connection of the internal wave field with the structure of their surface manifestations are described. ApparatusTo determine the relative variations of spectral density of dm surface waves two-dimensional optical spectrum analyzer (DOSA) was used, created in the Institute of Applied Physics. The distance between the hull of the vessel and the sea surface region to be observed was 30 meters, what allowed to eliminate the distortions due t o the waves induced by the vessel. The wavelength range of the analyzed surface waves was from 3.9 to 140 centimeters. The spectral density variations of the surface waves was analyzed in sector 120" wide and was registered in 480 spectral points: 24 directions of the surface wave propagation and 20 frequency channels in each directio...

This paper describes the construction of geophysical model function (GMF) for wind speed and surface stress retrieval at high winds from cross‐polarized radar backscatter at the water surface. The starting point is the laboratory experiment designed for the study of X‐band backscattering from water surface. In particular, it was shown that cross‐polarized normalized radar cross section (NRCS) keeps sensitivity to wind friction velocity at high winds alternatively to co‐polarized radar return. Basing on the analysis of the Doppler spectra and simultaneous measurements of parameters of surface waves, we suggest a hypothesis that at high winds the cross‐polarized backscattered signal is formed mainly due to scattering from wave breakers. The hypothesis is supported by the experimentally detected proportionality between the power of the scattered signal at cross polarization and the area swept by wave breakers. These results obtained in the laboratory environment are applied for constructing the similar dependencies for field conditions. Using the phenomenological statistical physics approach, a parameterization of active whitecap coverage fraction dependence on wind friction velocity is suggested. With the use of this parameterization, the empirical function expressing the cross‐polarized NRCS by u* is derived. Using the surface drag parameterization applicable at strong winds, this dependence is verified on the base of available data sets containing collocated satellite measurements of cross‐polarized C‐band NRCS and ground measurements of wind speed. GMFs for u* and U10 retrieval are suggested. Analysis shows that taking into account the angular dependence of cross‐polarized radar backscattered power improves the accuracy of wind speed and wind friction velocity retrieval.

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