Radar signatures of river outflow fronts

Weak hydrodynamic interaction theory is applied to describe signatures of outflow fronts like those of the river Rhine. The imaging model is two dimensional in position and wave number, allowing the inclusion of current shear. The full model is simplified to an analytical model that preserves the main features. Close to the river mouth, convergence dominates and the fronts always have a positive signature. Far from the river mouth, shear is most important and the front may be imaged as a bright or dark modulation, depending on the observation geometry. Model results agree quite well with ERS C-band SAR observations