USE OF SPACEBORNE SYNTHETIC-APERTURE RADAR IMAGERY OF THE SEA-SURFACEIN DETECTING THE PRESENCE AND STRUCTURE OF THE CONVECTIVE MARINE ATMOSPHERIC BOUNDARY-LAYER

Two distinct backscatter regimes are seen on a European remote sensing satellite ERS-1 C-band (5.6 cm) synthetic aperture radar (SAR) image of the sea surface during a time of fair synoptic-scale weather condit ions. One backscatter regime is mottled. In contrast to that, the seco nd backscatter regime is marbled. The authors hypothesize that the mot tled backscatter pattern is a characteristic SAR backscatter pattern l inked to the presence of the convective (i.e., statically unstable/con vective-eddy containing) marine atmospheric boundary layer (CMABL) and can be used to help determine CMABL structure [convective-eddy type ( cellular convection versus longitudinal rolls), eddy wavelength, and C MABL depth (via mixed-layer similarity theory for aspect ratio)]. The hypothesis linking the presence and structure of the CMABL to the mott led backscatter pattern on SAR imagery is validated by analyzing data from a number of sources gathered in the vicinity of the boundary betw een the mottled and marbled regimes on the SAR image.