1. School of Earth and Space Sciences, Peking University, Beijing 100871, People’s Republic of China.
2. Universities Space Research Association, Huntsville, AL 35805, USA.
3. High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307, USA.
4. Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People’s Republic of China.
5. Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK.
6. Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge CB3 0WA, UK.
7. Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, India.
8. Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA.
9. Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA.
10. Max Planck Institute for Solar System Research, 37077 Göttingen, Germany.