The University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242, USA
The University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242, USA
The University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242, USA; Charles University, Faculty of Mathematics and Physics, Prague, 18000 Czech Republic
The University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242, USA
Indian Institute of Geomagnetism, Dr. Nanabhai Moos Marg, Colaba, Mumbai, 400 005 India
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
The University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242, USA
The Blackett Laboratory, Imperial College, London, SWZ 2BZ United Kingdom