Radar Returns from the Sea Surface—Bragg Scattering and Breaking Waves

摘要: Abstract Recent ideas on the structure of equilibrium range wind-generated ocean waves are applied to question radar backscattered returns from sea surface. It is shown that backscattering cross section can be represented as sum separate contributions Bragg-scattering and individual breaking events:where θ angle incidence, ϕ direction observation relative wind, u* friction velocity κ wavelength; contribution increases linearly with spike cubically. The number spikes per unit time surface area for a given threshold intensity or duration proportional g−1u*3. Calibrated measurements median values σ0, which tend suppress contributions, have been made by Guinard et al. over wavelengths 70 3.4 cm. These scale consistently parameter (u*2κ/g)½ angles incidence greater than 30°, a...