1. Swedish Institute of Space Physics; Uppsala Sweden
2. International Space Science Institute, ISSI; Bern Switzerland
3. Max-Planck-Inst. f. Sonnensystemforschung; Katlenburg-Lindau Germany
4. Department of Physics and Astronomy; University of Leicester; Leicester UK
5. Department of Physics; University of Iowa; Iowa USA
6. ESA/STEC; Noordwijk Netherlands