Helene Asbjørnsen, Geophysical Institute, University of Bergen, and Bjerknes Centre for Climate Research, Bergen, Norway, Lea Svendsen, Geophysical Institute and Bjerknes Center for Climate Research, University of Bergen, Bergen, Norway, Bergen, Norway, Ingo Bethke, Geophysical Institute Bergen, Bergen, Norway and Yanchun He, Nansen Environmental and Remote Sensing Center, Bergen, Norway