Alexandra Laeng¹, Gabriele P Stiller², Thomas von Clarmann¹, Norbert Glatthor¹, Udo Grabowski¹ and John C Gille³, (1)Karlsruhe Institute of Technology, Karlsruhe, Germany, (2)KIT, Eggenstein-Leopoldsh, Germany, (3)NCAR, Boulder, CO, United States