Submesoscale Eddy Structures of Lake Ladoga According to Sentinel-1 Radar Data for a Warm Period of 2019–2022.

The results of analysis of spatiotemporal variability of submesoscale surface eddy structures from May to October of 2019–2022 in Lake Ladoga are summarized using more than 1000 Sentinel–1A/B high-resolution images as the original data. The wide occurrence of small eddy structures on the lake surface is revealed during the warm period of the year. In total, 496 surface eddies with an average diameter of 2 km are registered. More than 90% of the recorded eddies belong to the submesoscale variability range. Cyclonic rotation is typical of 84% of the structures. A seasonal maximum of eddy activity is registered during the stable stratification over most of Lake Ladoga. The eddies occur most frequently to the north and northeast of the Valaam Island in areas ~100 m deep but close to the seabed unevenness. During the spring thermocline, the eddies are often registered from the cold side of the frontal boundary indicating their important contribution to the water exchange and mixing processes. [ABSTRACT FROM AUTHOR]