1. Department of Aerospace Engineering Sciences University of Colorado Boulder Boulder CO USA
2. Laboratory for Atmospheric and Space Physics University of Colorado Boulder Boulder CO USA
3. Department of Space Physics, School of Electronic Information Wuhan University Wuhan China
4. Space Sciences Department The Aerospace Corporation El Segundo CA USA
5. Retired from Space Sciences Laboratory University of California Berkeley CA USA
6. Institut de Recherche en Astrophysique et Planétologie‐IRAP, Université de Toulouse, CNRS, UPS, CNES Toulouse France