Max-Planck-Institut für extraterrestrische Physik, P.O. Box 1312, Garching near Munich, 85741 Germany; University of Bergen, Department of Physics, Bergen, N- 5020 Norway
Max-Planck-Institut für extraterrestrische Physik, P.O. Box 1312, Garching near Munich, 85741 Germany
Boston University, Campus, Boston, MA 02215, USA
University of New Hampshire, Space Science Center, Durham, NH 03824, USA
University of California at San Diego, Campus, La Jolla, CA 94305, USA
Max-Planck-Institut für extraterrestrische Physik, P.O. Box 1312, Garching near Munich, 85741 Germany
University of New Hampshire, Space Science Center, Durham, NH 03824, USA
University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242, USA