1. TNO Built Environment and Geosciences, Utrecht, Netherlands
2. Rhenish Institute for Environmental Research at the University of Cologne, Cologne, Germany
3. Rutherford Appleton Laboratory, Chilton, Oxfordshire, United Kingdom
4. EUMETSAT, Darmstadt, Germany
5. Laboratoire des Sciences du Climat et de l’Environnement, Gif-sur-Yvette, France