A study of monomolecular slicks' damping effect on Doppler spectrum from one-dimensional time-varying rough sea surfaces

Abstract

The modeling of time-varying nonlinear sea surfaces damped by monomolecular sea slicks is presented in the present study by combining Lombardini et al. model that can predict the hydrodynamic damping of rough sea surfaces in the presence of monomolecular sea slicks and “choppy wave model” (CWM) that can describing the nonlinear interactions between ocean waves. On this basis, the influence of sea slick's damping on Doppler spectra of backscattered echoes from contaminated “choppy wave model” (CWM) nonlinear sea surfaces is investigated by comparison with the Doppler spectra of clean sea surfaces. Numerical simulations show a narrowing of the Doppler spectra of contaminated sea surfaces compared with those of clean sea. In addition, it is also indicated that the Doppler shifts in slicks can decrease or increase, depending on incidence angles.