Ring Structures on Baikal Ice and Local Upwelling Cases in Summer

• Published in: Water resources 2022-04, Vol.49 (2), p.184-192
• Main Authors: Granin, N. G., Zyryanov, D. V., Gnatovskii, R. Yu, Blinov, V. V.
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Cold water; Convection; Deep water; Development of Methods of Hydrophysical Hydrodynamics; Earth and Environmental Science; Earth Sciences; Gas hydrates; Hydrates; Hydrogeology; Hydrology/Water Resources; Ice; Ice cover; Ice formation; Ice thickness; Lake ice; Lakes; Low temperature; Navigation; Ocean circulation; Ring structures; Salinity; Satellite data; Satellite imagery; Satellite temperature; Satellites; Spaceborne remote sensing; Stratification; Summer; Surface temperature; Surface water; Temperature measurement; Temperature rise; Thickness; Upwelling; Waste Water Technology; Water Management; Water Pollution Control; Water temperature
• ISSN: 0097-8078; 1608-344X
• DOI: 10.1134/S0097807822020075

Ring structures on Baikal ice were found in satellite images in the period when ice cover thickness decreased (April). Analysis of satellite data on lake surface temperature in summer showed that local zones with lower temperature of water surface can sometimes be seen during the navigation period. According to field studies of ring structures on lake ice, they form and develop under the effect of currents which contribute to a decrease in ice thickness. The available data show that the generation of anticyclonic currents can be caused by a local rise of deep water. Similar phenomena can be seen in summer. Data of satellite temperature measurements show local drops of lake surface temperature in summer caused by upwelling. This is directly related with the rise of cold water from a deep zone. Depending on the temperature stratification (direct or reverse), upwelling contributes to the generation of either cyclonic or anticyclonic currents, respectively. The different directions of currents are due to the difference between temperature stratification in winter and summer. The formation of ring structures on ice and local drops of surface water temperature in summer are due to local water rises (upwelling). The upwelling can be caused by convection. The decrease in the density of the underlying water can be due to (a) temperature increase; (b) a decrease in salinity; (c) an increase in the concentration of methane dissolved in water in bottom zone. In addition, the upward flows can be due to ascending gas hydrates.