Characteristics of surface heat balance on the Senjagaike perennial snow patch of Mt. Hakusan for three summer seasons

Abstract

We conducted snow surveys and meteorological observations for three summer seasons on the Senjagaike perennial snow patch of Mt. Hakusan, located on the border of Ishikawa and Gifu prefectures. The characteristics of the surface heat balance in summer were assessed and the relationship between the snowmelt process and weather conditions was analyzed. Moreover, the influence of climatic conditions and heat balance characteristics on the annual change of the snow patch was examined. The 3-season average heat balance composition in summer was 447 W m^－2 net radiation (309 W m^－2 shortwave radiation and 138 W m^－2 longwave radiation), 140 W m^－2 sensible heat flux, 180 W m^－2 latent heat flux, and 39 W m^－2 rainfall heat flux. The 3-season average heat flux during rainfall ranged from 349 to 560 Wm^－2, and from 157 to 246 Wm^－2 during no rainfall, indicating that the snowmelt heat flux was larger than that during no rainfall. The net shortwave radiation contributed the most to the snowmelt in summer. However, the latent heat flux varied greatly depending on the frequency of severe weather events such as daily rainfall ≥ 50 mm and wind speed ≥7 m s^－1, which could result in differences in the accumulated snow height change in the summer season.