Local katabatic winds of the Russian Federation and their observation from space using SAR imagery.

Abstract

Data from the spaceborne synthetic aperture radars (SAR) provide new opportunities for observing and studying local katabatic winds (bora, foehn) in various marine regions of the Russian Federation and adjacent countries. 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 are displayed on SAR images. Satellite SAR images, in contrast to sub-satellite observations, make it possible to see the phenomenon in the coastal zones of seas and large lakes, judge the spatial scale of the phenomenon and determine a number of it quantitative characteristics. Analysis of collected SAR images shows that local winds, bora-like and foehn-like, have similar characteristics and cover vast areas of the inland and marginal seas of the Russian Federation. The similarity of the surface manifestations of the local winds, clearly speaks about the same physical and aerohydrodynamic mechanisms of their display on SAR images. It is shown that spaceborne SAR data and images, which are two-dimensional spatial patterns of “frozen wind”, are extremely useful for research and monitoring local winds over the seas of the Russian Federation, especially where the network of weather stations is extremely rare.