1. Institute for Environment and Sustainability, Joint Research Centre; European Commission; Ispra Italy
2. SRON Netherlands Institute for Space Research; Utrecht Netherlands
3. Institute for Marine and Atmospheric Research Utrecht (IMAU); Utrecht Netherlands
4. Netherlands Organisation for Applied Scientific Research (TNO); Utrecht Netherlands
5. Meteorology and Air Quality Department; Wageningen University and Research Centre; Wageningen Netherlands
6. Jet Propulsion Laboratory; California Institute of Technology; Pasadena California USA
7. Global Monitoring Division; NOAA Earth System Research Laboratory; Boulder Colorado USA
8. School of Engineering and Applied Science and Department of Earth and Planetary Sciences; Harvard University; Cambridge Massachusetts USA
9. CIRES; University of Colorado; Boulder Colorado USA
10. Max Planck Institute for Chemistry; Mainz Germany
11. Center for Isotope Research; University of Groningen; Groningen Netherlands
12. Max Planck Institute for Biogeochemistry; Jena Germany