Studying the spatial and temporal dynamics of water surface temperature of lake Onega by remote sensing methods

The materials on the water surface temperature of Lake Onega for a period of 35 years (from 1985 to 2020) were analyzed. Remote sensing data from two Internet sources with free access were used. Verification of data on full-scale water surface temperature measurements carried out from the ship was performed. A database on water surface temperature was compiled for 142 cells of the lake’s water area measuring 8*8 km. The equations of linear long-term trends in increasing the average monthly water surface temperature were calculated. The estimates obtained by remote sensing methods for the studied period for Lake Onega turned out to be close to the results of field observations. Cartograms were constructed demonstrating the severity of these trends in different parts of the Lake Onega water area. The most significant changes affected the Povenetsky Bay and the central part of Lake Onega. In these areas, lake waters began to heat up faster in early summer and cool down longer in autumn.