1. Finnish Meteorological Institute; Helsinki Finland
2. Department of Atmospheric, Oceanic and Space Sciences; University of Michigan; Ann Arbor Michigan USA
3. IRAP, UPS-OMP; University of Toulouse, CNRS; Toulouse France
4. Institute of Geophysics and Planetary Physics, Department of Atmospheric and Oceanic Sciences, University of California; Los Angeles California USA
5. State Key Laboratory of Space Weather, CSSAR, CAS; Beijing China
6. School of Astronautics, Beijing University of Aeronautics and Astronautics; Beijing China