5:15 PM - 7:15 PM
[ACC32-P06] Physical and chemical characteristics of meltwater paths on snowpack at Mt. Naeba in the Shinetsu region, Japan
Keywords:Mt. Naeba, snowpack, meltwater path, snow algae, melt water
During the snowmelt season, dendritic patterns visibly develop along the slopes on the surface of the snowpack. These patterns are likely to be formed when meltwater on the surface percolates within the snowpack by gravity and aggregates in specific flow paths. Along the meltwater on the surface flow paths, snow surfaces are often colored in red or green, which is the blooming of snow algae. Snow algae are cold-tolerant photosynthetic microbes living on snow and ice. They preferentially grow on the meltwater paths, probably because the conditions are suitable for their growth. However, the physical and chemical characteristics of meltwater paths are still unknown. This study aimed to describe the physical and chemical conditions of the meltwater path formed on the snowpack and to clarify its relationship to the growth of snow algae. Fieldwork was conducted on April 29, 2024, in the forested area at the foot of Mt. Naeba in the Shinetsu region, Japan. A linear meltwater path was observed on the snow surface in a deciduous forest. The physical conditions of the snow on the surface and below the surface were measured along a transect line across the meltwater path. Snow samples were continuously collected and their chemical properties and chlorophyll-a concentration were analyzed.
The snow depth along the meltwater path was approximately 60 cm. There was running water flow on the ground below the snowpack. The water content of the snow in the water path was about 60%, which was higher than the water content of the surrounding snow, which was about 10%. The oxygen stable isotope ratio of the snow at the meltwater path was not significantly different from that of the surrounding snow, but the electrical conductivity and phosphate ion concentration of the snow were higher at the meltwater path. Chlorophyll-a concentration was also higher on the surface of the meltwater paths than those in the surrounding snow, indicating that snow algae were growing intensively above the meltwater paths. These results suggest that the high water content and abundant nutrient concentrations along the meltwater paths may support the growth of snow algae.
The snow depth along the meltwater path was approximately 60 cm. There was running water flow on the ground below the snowpack. The water content of the snow in the water path was about 60%, which was higher than the water content of the surrounding snow, which was about 10%. The oxygen stable isotope ratio of the snow at the meltwater path was not significantly different from that of the surrounding snow, but the electrical conductivity and phosphate ion concentration of the snow were higher at the meltwater path. Chlorophyll-a concentration was also higher on the surface of the meltwater paths than those in the surrounding snow, indicating that snow algae were growing intensively above the meltwater paths. These results suggest that the high water content and abundant nutrient concentrations along the meltwater paths may support the growth of snow algae.