Heat reserves of lakes of Belarus

Abstract The article concerns changes in the heat reserves of the lakes of Belarus in connection with the emerging trends of global warming. When calculating the heat reserves of lakes the method proposed by the Hydromet service was adopted. This technique allows the heat reserves of lakes to be determined with greater accuracy for subsequent comparison and discovery of spatio-temporal connections. The heat reserves were calculated for five lakes whose temperature regime has been constantly monitored. A quantitative assessment of changes in heat reserves for the period of instrumental observations was obtained. It was found that the average range of fluctuations in the gradients of heat reserves of lakes for the Belarusian Lake District ranges from 2.71×1015 J in May to 54.56×1015 J in August; for Belarusian Polesie – from 2.78 to 4.17×1015 J, respectively. The cyclicity of fluctuations in the heat reserves of lakes of Belarus was revealed and found to be short-period (3-5 years) and long-period (10-11 years) cycles.