1. Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
2. Department of Physics and Astronomy, The Open University, Milton Keynes, UK.
3. Instituto de Astronomia, Geofisica e Ciencias Atmosféricas, Universidade de São Paulo, São Paulo, Brazil.
4. Planetary and Space Science Research Institute, Open University, Milton Keynes, UK.
5. INAF/Osservatorio Astrofisico di Arcetri, Firenze, Italy.
6. INAF/Osservatorio Astrofisico di Catania, Catania, Italy.
7. Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast, UK.