1. Department of Meteorology Stockholm University SE‐106 91 Stockholm Sweden
2. Department of Geography University of Cambridge Downing Place Cambridge CB2 3EN UK
3. Finnish Meteorological Institute P.O. Box 1627 FI‐70211 Kuopio Finland
4. Helsinki Region Environmental Services (HSY) P.O. Box 100 FI‐00066 HSY Finland
5. Remote Sensing Division, Research Department Swedish Meteorological and Hydrological Institute (SMHI) 60 176 Norrköping Sweden
6. Department of Applied Environmental Science Stockholm University SE‐106 91 Stockholm Sweden