THERMOHYDRODYNAMICS OF LAKES IN THE PERMAFROST ZONE OF RUSSIA: RETROSPECTIVE ASSESSMENT AND FORECAST OF CHANGES IN THE 21 CENTURY

The objective of the work is a retrospective and prognostic assessment of thermal and ice characteristics of lakes in the permafrost zone of the Russian Federation based on satellite information and mathematical modeling. The geographic location and area of the lake are determined using satellite images. Using geostatistical dependencies based on the area values of the reservoir, its average depth is found. The obtained value of the average depth is used as a parameter for calculating the thermohydrodynamic characteristics of the lake and its bottom sediments using the one-dimensional thermohydrodynamic model FLake. The ERAS meteorological reanalysis data are the basis for the retrospective assessment of the reservoir characteristics; the forecast of the consequences of climate change by the end of the 21 century is made on the basis of SSP greenhouse gas emission scenarios into the atmosphere. Retrospective and prognostic calculations of the characteristics of unexplored and poorly studied lakes are performed without additional verification of the model and do not require labor-intensive in-kind measurements in hard-to-reach areas of permafrost. Retrospective (1940–2015) and prognostic (2016–2100) calculations of thermohydrodynamic characteristics of water and bottom sediments for hypothetical lakes located in the centroids of the studied lake regions were performed for 15 main lake regions covering the permafrost zone of Russia. The results of calculations of water mass heating and ice cover formation in lakes in the regions under consideration correspond to modern ideas about global warming in the northern regions of our country.