*Michio Kawamiya¹, Kaoru Tachiiri¹, Tomohiro Hajima¹, Junichi Tsutsui², Takashi Arakawa⁴, Tokuta Yokohata³ (1.Japan Agency for Marine-Earth Science and Technology, 2.Central Research Institute for Electric Power Industry, 3.National Institute for Environmental Studies, 4.Research Organization of Information Science and Technology)