Ratios of Mg2+/Na+ in the snow cover at Murododaira, Mt. Tateyama, Japan: On the possibility of an indicator of chemical leaching

Measurements of the concentrations of major ions in the snow pits at Murododaira (altitude, 2,450 m), Mt. Tateyama, near the coast of the Japan Sea in Central Japan, have been taken each April. Snowmelt usually occurs after May near the summit of Mt. Tateyama. However, the snow wall in the 2004 pit was mainly composed of melt forms (granular snow), and snow temperature was 0 ℃ in all layers; therefore, the chemical components in the snow were affected by leaching. Many samples taken from the 2004 pit showed that the ratio of Mg 2 ＋ /Na ＋ was lower than that in sea salt, whereas the loss of Mg 2 ＋ has hardly been observed in the snow cover at Murododaira in other years. The results suggest that the Mg 2 ＋ /Na ＋ ratio can be used as an indicator of the leaching of chemical compositions in a snowpack, such as a boring core, at an Alpine site in Japan.