Formation features of Lake Baikal hydrometeorological regime in the modern period

Abstract

We analyzed the main features of climate fluctuations near Lake Baikal and water regime components between 1980 and 2023. The analysis indicated climate warming with the highest rates of air temperature rise during the cold season of the year and an increase in climate aridity or a decrease in annual and monthly atmospheric precipitation. During the Southern Hemisphere cyclones and the development of convective or orographic clouds, the spatial heterogeneity of summer atmospheric precipitation increased. In winter, under the dominant influence of the Asian monsoon anticyclone, these differences were minimal. Correlating with climate change, the ratio between the lake’s water balance components transformed, determining the features of seasonal and interannual fluctuations in its water level. The inflow of surface waters to the lake and the runoff from it decreased, while the evaporation from the surface of the water body, on the contrary, increased. The heating of the lake’s water masses increased, especially at its northern end distinguished by the lower wind activity. Due to the later freezing of the lake and earlier ice breakup (up to 20 days), the ice cover period reduced. We observed climate change in circulation factors at Lake Baikal, including an increase in the activity of migratory cyclogenesis in the cold season of the year and upper-level anticyclogenesis in the warm season, where the frequency of blocking processes also increased. Keywords: air temperature, precipitation, inflow, evaporation, water level.