A comparison of wind wave spectra used in ocean remote sensing modeling

Nowadays, remote sensing techniques from space become routine application to get valuable information on ocean surface processes. Nevertheless, knowledge about electromagnetic mechanisms depending upon water surface representation are needed to properly interpret those information. Consequently, a reliable ocean surface description in terms of wind wave vector spectrum is necessary to correctly model hydrodynamic properties near the water surface. This two-dimensional spectrum should account for long waves as well as short waves. As well known, capillary-gravity waves play a major role in microwave scattering. Thus, a reliable interpretation of microwave measurements is constrained to accurate modeling of the capillary-gravity portion of the wind wave directional spectrum. Although gravity waves have been accurately measured and properly modeled in the past, a great effort is still needed in both measurements and modeling of short waves. In spite of the rarity of direct short wave measurements, one still can find in the literature some proposed ocean wave spectra. Comparison of those spectra is reported, along with remarks that may guide investigators who are concerned with models elaboration of geophysical processes at the air-water interface.