Thermal regimes of lakes in the southern and eastern part of the Baltic Sea catchment area during the period of climate change

  The study covered eleven lakes located in northern Poland and Belarus, aiming to determine the degree and trends of surface water temperature changes for the years 1971–2020 and lake ice cover  for  the  period  of  1961–2020  under  the  influence  of  ongoing  climate  changes.  The  analysis focused on changes and trends in average monthly surface water temperatures (SWT), as well as changes  in  the  onset  and  end,  duration  and  maximum  thickness  of  ice  cover.  The  average  annual surface water temperature increased in the lakes by an average of 0.044°C per  year. The lake with the highest trend is Chervonoe, at with 0.066°C per year, while the lowest is 0.029°C per year in Lake Hańcza. The ice  cover duration  showed a decrease of 0.6 days per year, and there was a reduction in maximum ice thickness of 0.27 cm per year