[1] NOAA, ESRL, Div Chem Sci, Boulder, CO USA
[2] Chalmers Univ Technol, S-41296 Gothenburg, Sweden
[3] Natl Ctr Atmospher Res, Earth Observing Lab, Boulder, CO 80307 USA
[4] Univ Colorado, CIRES, Boulder, CO 80309 USA
[5] Aerodyne Res Inc, Billerica, MA USA