1. Leibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, Germany
2. University of Hawaii, Department of Oceanography, Honolulu, HI 96822, USA
3. NASA Langley Research Center, Hampton, VA 23681, USA
4. Royal Netherlands Meteorological Institute (KNMI), 3730 AE de Bilt, Netherlands
5. Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe, Germany
6. Max Planck Institute for Chemistry, Atmospheric Chemistry Division, 6500 Mainz, Germany