1. 1Department of Meteorology and Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
2. 2Department of Engineering Mechanics, KTH Royal Institute of Technology, Stockholm, Sweden
3. 3Cooperative Institute for Research in Environmental Sciences, University of Colorado and Physical Sciences Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
4. 4Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Bremerhaven/Potsdam, Germany
5. 5European Centre for Medium-Range Weather Forecasts, Reading, UK
6. 6U.S. Naval Research Laboratory, Marine Meteorology Division, Monterey, CA, USA
7. 7School of Environmental Sciences, University of East Anglia, Norwich, UK
8. 8Geophysical Institute, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway
9. 9Meteorological Research, Finnish Meteorological Institute, Helsinki, Finland