Measurements of the concentrations of major ions in the snow pits at Murododaira (altitude, 2,450m), 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°C 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 Mg2+/Na+ was lower than that in sea salt, whereas the loss of Mg2+ has hardly been observed in the snow cover at Murododaira in other years. The results suggest that the Mg2+/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.
During spring 2014, we drilled an ice core on the northwestern Greenland Ice Sheet, recovering a core of total length 225m. We also conducted stratigraphic observations, measurements of the density of the ice core, near-infrared photography of the ice core, preparation of liquid samples for chemical analysis, and measurements of borehole temperature. The pore close-off depth was 60m, and the temperature in the borehole was −25.6°C at a depth of 10m. In addition, we conducted snow-pit observations, ice-velocity and surface-elevation measurements using the global positioning system (GPS), meteorological observations, and installation of an automated weather station (AWS).