Deeper and earlier penetrations of oxygen ions than protons into the inner magnetosphere Observed by Van Allen probes.

Kenji Mitani, Nagoya-university, Institute for Space-Earth Environmental Research, Nagoya city, Japan, Kanako Seki, University of Tokyo, Research Center for Advanced Science and Technology, Bunkyo-ku, Japan, Kunihiro Keika, University of Tokyo, Graduate School of Science, Bunkyo-ku, Japan, Louis J Lanzerotti, New Jersey Institute of Technology, Center for Solar-Terrestrial Research, Newark, NJ, United States, Matina Gkioulidou, Johns Hopkins Applied Physics Laboratory, Laurel, United States, Donald G Mitchell, JHU/APL, Laurel, MD, United States and Craig Kletzing, University of Iowa, Physics and Astronomy, Iowa City, United States