1. Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, United States
2. Smead Aerospace Engineering Sciences Department, University of Colorado, Boulder, Colorado 80303, United States
3. Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
4. Department of Physics, University of Colorado, Boulder, Colorado 80303, United States
5. Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
6. Institute of Geological Sciences, Frei Universität Berlin, 12249 Berlin, Germany
7. Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Hungary
8. Institute for Space Systems, Stuttgart University, 70569 Stuttgart, Germany