1. Geophysical Institute; University of Alaska Fairbanks; Fairbanks Alaska USA
2. Department of Atmospheric Sciences; University of Alaska Fairbanks; Fairbanks Alaska USA
3. Atmospheric Chemistry Division, National Center for Atmospheric Research; Boulder Colorado USA
4. Laboratory for Atmospheric and Space Physics; University of Colorado; Boulder Colorado USA
5. High Altitude Observatory, National Center for Atmospheric Research; Boulder Colorado USA
6. EPhysLab, Facultad de Ciencias; Universidade de Vigo; Ourense Spain