Front detection in MODIS imagery of the Black Sea

Satellite imagery of visible and infrared ranges frequently visualizes the manifestations of hydrological fronts at different spatial scales. Despite high availability of optical-range satellite imagery and the great interest of researchers to the Black Sea hydrodynamics, hydrological fronts in this basin have not got a thorough consideration so far. In the present paper, Aqua Moderate Resolution Imaging Spectrometer (MODIS) data were implemented to get some general information on thermal and optical frontal zones in the Black Sea. The edge detection was performed by means of the Sobel operator. Obtained in such a way gradient norms were summed and normalized by the number of covering images. As a result, the areas of the highest front density and the most persistent synoptic- and mesoscale circulation features were retrieved.