Critical Analysis of Remote Sensing Data of Chlorophyll-a in the Surface Waters of Lake Onego

The work is devoted to a comparative analysis of processed satellite data of chlorophyll-a concentration for the period 1998–2022 and field data collected during expeditions by the Laboratory of Hydrobiology of the Northern Water Problems Institute of the Karelian Research Centre of the Russian Academy of Sciences and published in scientific periodicals. GlobColour datasets provided by the Copernicus Marine Environmental Monitoring Service and datasets of the Ocean Color Climate Change Initiative project of the European Space Agency were used. The comparison results showed that GlobColour data are more consistent with field data of the Lake Onego than OC-CCI data: average absolute error values for the period 1998–2020 are 2.97 µg/l (n = 509) and 5.24 µg/l (n = 33) respectively.