[A-CC20] Glaciology

[ACC20-P10] Differences of physical and chemical conditions between green and red algal snow appeared in mountain regions in Japan

*Akane Watanabe¹, Nozomu Takeuchi¹, Sota Tanaka¹, Tomomi Nakashima¹, Kenshiro Miyauchi¹ (1.Graduate School of Science, Chiba University)

Keywords:Snow algae, Mt. Gassan, Mt. Tateyama

Snow algae are photosynthetic microbes inhabiting alpine and polar snow fields. They usually bloom on melting snow surface and change its color to green or red. The color of snow is determined by pigment composition in the algal cells and is associated with taxa of algae, the stages of algal life cycle, and/or response to the environment conditions. Green or red algal snow appears widely in mountain regions in Japan. However, physical and chemical conditions of the appearance of green or red algal snow is still unknown.
The purpose of this study is to describe the algal community and environment conditions of green and red algal snow appeared in mountain regions in Japan. We collected the colored snow samples in the melting season of 2015 in Mt. Gassan (green snow) in Yamagata prefecture and in Mt. Tateyama (red snow) in Toyama prefecture, Japan. We analyzed microscopic morphology and abundance of snow algal cells, chlorophyll-a concentrations, absorption spectrum of their pigments, and soluble chemical composition in the snow samples. Both green and red snow samples contained abundant snow algal cells. The depth of the snow at the study sites was more than 120 cm. The vertical distribution of algal cells in the snow pack showed that they were abundant at the surface layers. There were significant differences in ammonium and phosphate concentrations in the surface snow between green and red snows. This suggest that nutrient condition is one of the factors to determine the color of algal snow.