Xin Cao, University of Iowa, Iowa City, IA, United States, Jasper S Halekas, University of Iowa, Department of Physics and Astronomy, Iowa City, IA, United States, James P McFadden, Univ California Berkeley, Berkeley, CA, United States and Karl-Heinz Glassmeier, Technische Universität Braunschweig, Braunschweig, Germany