1. Swedish Institute of Space Physics Uppsala Sweden
2. Departamento de Ciencias Espaciales Instituto de Geofísica Universidad Nacional Autónoma de México Ciudad Universitaria Ciudad de México Mexico
3. Division of Space and Plasma Physics School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm Sweden
4. IRAP UPS CNRS Toulouse France
5. Mullard Space Science Laboratory University College London London UK