Thomas Thorp¹, Steve Arnold¹, Dominick V Spracklen¹, Richard Pope¹, Luke Conibear¹, Christoph Knote², Boris D Belan³, Mikhail Arshinov⁴ and Andrei I Skorokhod⁵, (1)University of Leeds, Leeds, United Kingdom, (2)Ludwig-Maximilians-University (LMU), Meteorological Institute, Munich, Germany, (3)V.E. Zuev Institute of Atmospheric Optics SB RAS, Tomsk, Russia, (4)Russian Academy of Sciences, V. E. Zuev Institute of Atmospheric Optics, Tomsk, Russia, (5)A.M.Obukhov Institute of Atmospheric Physics RAS, Moscow, Russia