1. Department of Atmospheric and Oceanic SciencesUniversity of California Los Angeles CA USA
2. now at Institute for the Study of Earth, Oceans, and SpaceUniversity of New Hampshire Durham NH USA
3. Departamento de Física, Facultad de CienciasUniversidad de Chile Santiago Chile
4. Heliophysics Science DivisionNASA Goddard Space Flight Center Greenbelt MD USA
5. Institute for the Study of Earth, Oceans, and SpaceUniversity of New Hampshire Durham NH USA
6. Laboratory for Atmospheric and Space PhysicsUniversity of Colorado Boulder Boulder CO USA