Local Katabatic Winds of the Russian Federation and Their Observation Using Synthetic Aperture Radar Imagery

Abstract

Data from synthetic aperture radars (SAR) provide new opportunities for observing and studying local katabatic winds (bora and foehn) over the seas in different regions of the Russian Federation and adjacent marine basins. The impact of these winds on the characteristics of small-scale wind waves leads to the formation of characteristic manifestations on the sea surface, which in turn can be seen in SAR images. Satellite SAR data, unlike subsatellite observations, make it possible to see the phenomena in coastal zones and large lakes, estimate their spatial scales, and determine a number of quantitative characteristics. The analysis of the collected SAR images shows that bora-like and foehn-like local winds have similar characteristics and cover vast areas of the inland and marginal seas of the Russian Federation. The similarity of the manifestations of local winds clearly indicates the same physical and aerohydrodynamic mechanisms of their onset and display on SAR images. It is shown that spaceborne SAR data, which are 2D patterns of the ‘frozen wind’, are extremely useful for studying and monitoring local winds over the seas, especially where the network of weather stations is extremely sparse.