HR: 0800h
AN: C21C-1131    [Abstracts]
TI: Distribution of Red Snow (snow algal blooming) on the Harding Ice field in Alaska Derived From a Satellite Image
AU: * Takeuchi, N
EM: takeuchi@chikyu.ac.jp
AF: Research Institute for Humanity and Nature, 335 Takashimacho Kamigyoku, Kyoto, 602-0878 Japan
AU: Dial, R
EM: roman@alaskapacific.edu
AF: Alaska Pacific University, 4101 University Drive, Anchorage, AK 99508 United States
AU: Kohshima, S
EM: kohshima@bio.titech.ac.jp
AF: Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551 Japan
AU: Segawa, T
EM: takasega@bio.titech.ac.jp
AF: Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551 Japan
AU: Uetake, J
EM: juetake@bio.titech.ac.jp
AF: Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551 Japan
AB: Red snow caused by snow algal blooming is a common phenomenon on glaciers and snowfields in the world. The distribution and quantification of algal snow are important not only for understanding of their ecology but also geophysical study of glaciers in terms of albedo reduction of snow and ice. Here, we present distribution of red snow on the Harding Ice field in Alaska derived from a SPOT satellite image. In situ observation on the ice field conducted in August, 2001 revealed that significant visible red snow occurred on the snow surface of the icefield, particularly in the area near snow line. Measurements of spectral reflectivity of the surface showed that the reflectance ratio of the wavelengths of bands 1 and 2 of the SPOT sensor (545 and 645 nm) significantly correlated with the snow algal biomass on the surface. Thus, the reflectivity ratio of the bands 1 and 2 of the SPOT image could be used to evaluate distribution of red snow. Longitudinal profile of the ratio along an outlet glacier of the icefield derived from a SPOT image showed that higher level occur in the snow area near snow line, suggesting occurrence of red snow in the area. This area is consistence with in situ observation of red snow distribution. Mapping of the reflectivity ratio on the ice field using the SPOT image showed that red snow occurred in the snow area near snow line on entire ice field, and particularly in the northeast side of the icefield.
DE: 1621 Cryospheric change (0776)
DE: 1640 Remote sensing (1855)
DE: 1827 Glaciology (0736, 0776, 1863)
DE: 4840 Microbiology and microbial ecology (0465)
DE: 4908 Albedo
SC: Cryosphere [C]
MN: Fall Meeting 2005