[M-IS11] Mountain Science

[MIS11-P09] Spectral reflectance in the visible wavelength range of green and yellow snow formed by snow algal blooms

*Ryohei Abe¹, Nozomu Takeuchi¹ (1.Chiba University)

Keywords:Snow algae, Colored snow, Green snow, Yellow snow, Spectral reflectance, Mt. Naeba

Snow algae are photosynthetic microorganisms growing on the surface of glaciers and snowpacks. Because the cells of snow algae contain various pigments, their blooms change the color of snow to green, yellow, or red. The coloring of snow by these algae is collectively called colored snow. Green and yellow snows are typical colored snow in the forest area of Japan and are usually formed by the algae genus Chloromonas and genus Ochromonas, respectively. As they have different pigment compositions, their spectral reflectances in the visible wavelength range show distinct curves. However, there has been no study to focus on their difference. This study aims to clarify the relationship between the spectral reflectance of colored snow and the algal community, especially to focus on green and yellow snow in Mt. Naeba in Nagano Prefecture, Japan. The spectral reflectances of green and yellow snow showed very similar curves but slightly different features at wavelengths of 675 nm and 450 nm. The absorption feature at the wavelength of 675 nm is likely to be caused by the difference in chlorophyll pigments of the algal cells. The absorption also appeared in the range between 450 nm and 570 nm in both snows, but there were different curves in the range for green and yellow snows. The difference is probably due to the presence of chlorophyll c and xanthophyll pigments in the yellow snow algae.