1. School of Earth and Atmospheric Sciences; Georgia Institute of Technology; Atlanta Georgia USA
2. Now at Atmospheric Sciences and Global Change Division; Pacific Northwest National Laboratory; Richland Washington USA
3. Institute for the Study of Earth, Oceans, and Space; University of New Hampshire; Durham New Hampshire USA
4. NASA Langley Research Center; Hampton Virginia USA
5. Institut fuer Ionenphysik und Angewandte Physik; Innsbruck Austria
6. Oak Ridge Associated Universities (ORAU); Oak Ridge Tennessee USA
7. School of Civil and Environmental Engineering; Georgia Institute of Technology; Atlanta Georgia USA