*Sakakura Kotaro¹, Kanako Seki¹, Shotaro Sakai¹, David A Brain², James P McFadden³, James S Halekas⁴, Gina A Dibraccio⁵, Bruce M Jakosky² (1.Department of Earth and Planetary Science, Graduate School of Science, The university of Tokyo, 2.Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, Colorado, USA., 3.Space Sciences Laboratory, University of California, Berkeley, California, USA., 4.Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA., 5.Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA.)