Signature of Large Aspect Ratio Roll Vortices in Synthetic Aperture Radar Images of Tropical Cyclones

Synthetic aperture radar images of tropical cyclones have been processed into high-resolution surface wind vector fields. Examination of the surface wind divergence and wind stress curl show that wind-aligned, O(10 km) wavelength, banded features are present throughout the images. These signatures are consistent with what would be expected from boundary layer roll vortices, except that their wavelengths are much too large. This paper argues that large aspect ratio roll vortices are responsible for these surface wind signatures and proposes a mechanism by which they are likely formed.