1. Department of Climate and Space Sciences and Engineering University of Michigan Ann Arbor Michigan USA
2. Los Alamos National Laboratory Los Alamos New Mexico USA
3. Department of Space Physics Institute of Atmospheric Physics CAS Prague Czech Republic
4. Faculty of Mathematics and Physics Charles University in Prague Prague Czech Republic
5. School of Physics and Astronomy University of Minnesota, Twin Cities Minneapolis Minnesota USA
6. Department of Physics and Astronomy University of Iowa Iowa City Iowa USA
7. Department of Mathematics Eastern Michigan University Ypsilanti Michigan USA