Ayako Yamamoto, JAMSTEC Japan Agency for Marine-Earth Science and Technology, Kanagawa, Japan, Masami Nonaka, Application Laboratory, JAMSTEC, Yokohama Kanagawa, Japan, Akira Yamazaki, JAMSTEC, Yokohama, Japan, Patrick Martineau, University of Tokyo, Japan, Young-Oh Kwon, Woods Hole Oceanographic Institution, Physical Oceanography Department, Woods Hole, MA, United States, Hisashi Nakamura, University of Tokyo, Bunkyo-ku, Japan and Bunmei Taguchi, University of Toyama, Faculty of Sustainable Design, Toyama, Japan