Estimation of the energy used to melt snow in the Tien Shan mountains and Japanese Islands

The heat needed to melt snow over the Tien Shan mountains and Japanese Islands for 10-day period (TDP) was estimated. Melting curves and a map of snowmelt duration were obtained through the long-term data from 79 stations in the Tien Shan mountains and 20 stations in the Japanese Islands. At high elevations in the mountains, about 40% of the snow melts during penultimate 10 days of snow cover. In the Japanese Islands, about 80% of the snow melts during the last 20 days of snow cover. Over the mountains, 0.13×104 MJ m2 year−1 is needed to melt snow in the northern and western Tien Shan where maximum snow accumulation occurred. The volume of air cooled 10 °C by snowmelt amounted to 4.4×106 km3 year−1 over the Tien Shan mountains and 3×106 km3 year−1 over the Japanese Islands. The most significant impact of snowmelt on air temperature was observed at an elevation of 2500 m in the western and northern Tien Shan. Air that was cooled 10 °C could reach an elevation of 2.1 km day−1. Over the Japanese Islands, energy losses from snowmelt amounted to 0.26×1014 MJ year−1 and the maximum occurred over Honshu Island. The heat loss from snowmelt in the Tien Shan mountains and Japanese Islands amounted to about 2/3 of heat loss in the Eurasian continental plains.