IDENTIFICATION OF FRONTAL ZONES POSITION ON THE SURFACE OF THE BARENTS SEA ACCORDING TO IN SITU AND REMOTE SENSING DATA

In the paper analysis of position and characteristics of frontal zones in the Barents Sea from 2008 to 2018 is presented according to sea surface temperature and salinity data obtained as a result of satellite (temperature only) and in situ (along standard oceanographic sections no. 3, 6, 19) measurement. We perform numerical experiments to evaluate the informativeness of the results of using two front identification methods. The first one builds the fields of the modules of the horizontal gradients of the sea surface temperature, the second one generates contours (fronts). The latter is based on digital image processing method to identify boundaries with contextual median filtering and Sobel differentiation performing. While the first method requires human expert to analyse constructing maps of the distribution of horizontal gradient module to obtain fronts, another tends to retrieve fronts automatically. In the area of the Medvezhinsky Rise, the results of the methods are well concerted for the period under consideration. Taking into account the spatial resolution and significant temporal averaging of satellite data, the boundary method turned out to be less informative in comparison with another one. When processing data on the distribution of sea surface temperature as close as possible to measurement dates, a period of time can be corrected for the position of hydrological stations when working in the Polar Frontal Zone area. The best result in revealing the current position of the frontal zone can be achieved with simultaneous use of contact and satellite sensing data and both front identification methods.

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