1. Department of Mathematics and Statistics; Memorial University of Newfoundland; St. John's Newfoundland Canada
2. Department of Computer Science; University of Calgary; Calgary Alberta Canada
3. Mullard Space Science Laboratory; University College London; Holmbury St. Mary, Dorking, Surrey UK
4. British Antarctic Survey; Natural Environment Research Council; Cambridge UK
5. Department of Atmospheric Sciences; University of California; Los Angeles California USA
6. Belgian Institute for Space Aeronomy; Brussels Belgium
7. Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA