[1] Univ Paris 06, UPMC, F-75005 Paris, France
[2] CNRS, UMR 7620, Serv Aeron, F-75005 Paris, France
[3] NOAA, Earth Syst Sci Lab, Boulder, CO 80305 USA
[4] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80305 USA
[5] UPS, CNRS, UMR 5560, Lab Aerol, F-31000 Toulouse, France
[6] CNRS, CEFE, IRD, Montpellier, France
[7] JRC, Ispra, Italy