1. Department of Earth and Environmental Science; Hirosaki University; Hirosaki, Aomori; Japan
2. Institute of Observational Research for Global Change; Japan Agency for Marine-Earth Science and Technology; Yokosuka; Japan
3. Okinawa Subtropical Environment Remote-Sensing Center; National Institute of Information and Communications Technology; Onna, Okinawa; Japan
4. Division of Geoenvironmental Sciences, Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba; Japan