*Moto Kawamata¹, Yusuke Suganuma^2,1, Koichiro Doi^2,1, Keiji Misawa^2,1, Motohiro Hirabayashi², Akihisa Hattori¹, Takanobu Sawagaki³ (1.Department of Polar Science, School of Multidisciplinary Science, SOKENDAI (The Graduate Unversity for Advanced Studies), 2.National Institute of Polar Research, 3.Hosei University)