Investigation of Atmospheric Gravity Waves and Rotors in the Marine Boundary Layer using Spaceborne Synthetic Aperture Radar Images

Atmospheric gravity waves (AGWs) propagating in the marine boundary layer leave fingerprints on the ocean surface which are detectable by synthetic aperture radar (SAR). They are associated with a variable wind speed at the sea surface which modulates the small-scale sea surface roughness and thus the backscattered radar power. We present 5 examples of SAR images acquired by the Advanced Synthetic Aperture Radar (ASAR) onboard the European Envisat satellite which show that spaceborne SAR images contain valuable information on the generation of AGWs and on the extent and shape of AGW fields. Furthermore, we show how quantitative information on the sea surface wind speed fluctuations induced by AGWs can be extracted from SAR images of the sea surface.