Signatures of resonant and non-resonant scattering mechanisms on radar images of internal waves
The results of two polarization airborne radar imagery tests of the ocean surface obtained during the JUSREX'92 experiment are presented. It is shown that the traditional composite surface model with small-scale 'Bragg' waves superposed over larger gravity waves can not explain either the contrasts of internal wave surface manifestations in conditions of a stable atmospheric boundary layer at low grazing angles (LGA), or the apparent difference between the images obtained at different polarizations in unstable atmospheric conditions. We attribute this discrepancy to the presence of mesoscale steep waves, which produce non-resonant scattering and make different relative contributions to the total cross sections for the two polarizations. The possibility of distinguishing between surface manifestations of atmospheric and oceanic origin is also discussed.