Monika Ewa Szelag¹, Viktoria Sofieva¹, D A Degenstein², Chris Roth³, Sean M Davis⁴ and Lucien Froidevaux⁵, (1)Finnish Meteorological Institute, Helsinki, Finland, (2)University of Saskatchewan, Department of Physics & Engineering Physics, Saskatoon, SK, Canada, (3)University of Saskatchewan, Saskatoon, SK, Canada, (4)Chemical Sciences Division, NOAA Earth System Research Laboratory; Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States, (5)Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States