Application of a SAR image archive to climatological analysis of coastal wind storms

This study uses the high-resolution all-weather surface wind field mapping capability of SAR to detect and quantitatively describe the strong mountain-parallel, low-level mesoscale wind maxima, commonly called barrier jets that occur along the synoptically windward slopes of Alaska´s coastal mountain ranges. SAR reveals that there are two classes of this phenomenon: pure barrier jets caused by terrain blocking of on-shore (i.e. upslope) flow and hybrid jets resulting from the cyclonic turning of off-shore gap flow until it becomes shore-parallel. This paper includes a five-year study from May 1998 through April 2003 of coastal barrier and hybrid jet occurrence in the Gulf of Alaska. Temporal and spatial distributions of banner jet and hybrid occurrence highlight the favored seasons and locations for jet formation and explanations for shape of each distribution are given. The climatological values of structural characteristics of barrier and hybrid jets including strength and width are also computed