Institution: | a Swedish Institute of Space Physics, Box 812, SE-98128 Kiruna, Sweden b Space Physics Laboratory, Vikram Sarabhai Space Center, Trivandrum 695 022, India c Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland d Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Sagamihara, Japan |