*Akane Tsushima¹, Masashi Niwano¹, Teruo Aoki², Nozomu Ohkawara¹, Tomonori Tanikawa¹, Sumito Matoba³, Kouji Adachi¹, Takeshi Kinase¹, Koji Fujita⁴ (1.Meteorological Research Institute, 2.National Institute of Polar Research, 3.Institute of Low Temperature Science, Hokkaido Univ., 4.Graduate School of Environmental Studies, Nagoya Univ.)