Mark Lunt, University of Edinburgh, Edinburgh, EH9, United Kingdom, Paul I Palmer, University of Edinburgh, School of Geosciences, Edinburgh, United Kingdom, Liang Feng, University of Edinburgh, NCEO, Edinburgh, EH9, United Kingdom, Jochen Landgraf, SRON Netherlands Institute for Space Research, Utrecht, Netherlands and Pepijn Veefkind, Royal Netherlands Meteorological Institute, De Bilt, Netherlands