1. Norwegian Institute for Air Research; Kjeller Norway
2. Global Monitoring Division, Earth System Research Laboratory (ESRL); National Oceanic and Atmospheric Administration; Boulder Colorado USA
3. Laboratoire des Sciences du Climat et de l'Environnement; Gif-sur-Yvette France
4. Centre for Australian Weather and Climate Research/Commonwealth Scientific and Industrial Research Organisation; Aspendale Victoria Australia
5. Massachusetts Institute of Technology; Cambridge Massachusetts USA
6. Scripps Institution of Oceanography; University of California, San Diego; La Jolla California USA
7. National Institute for Environmental Studies; Tsukuba Japan
8. University of Bristol; Bristol United Kingdom