Studies of rainfall footprints on the sea conducted by spaceborne SAR "Almaz" and shipborne microwave radiometers

The present paper contains the results obtained in Gulf Stream region under intense rainfall conditions in July-August, 1992. The spaceborne SAR "ALMAZ" images and microwave data of measurements conducted by research vessel "Academic Ioffe" are analyzed. Shipborne active and passive remote instruments were probing the sea surface in 0.6-8 cm wave length range of electromagnetic waves. This made it possible to investigate the rainfall influence on a damping of surface waves in different frequency ranges and minimized also the cloud influence on estimates of rain rate with brightness temperature data. Joint analysis of spaceborne SAR observations, microwave shipborne and in situ data allowed some SAR images features associated with rainfall to be explained. The radiobrightness and backscattering of sea surface perturbed by rain was also studied.