Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5428620 | Journal of Quantitative Spectroscopy and Radiative Transfer | 2013 | 4 Pages |
â¢Transition frequencies were measured for CO2 lines in the (30013)â(00001) band.â¢These absolute transition frequencies were linked to a cesium atomic clock.â¢A global fit was performed to numerous CO2 bands in the near- and mid-infrared.
Absolute transition frequencies were measured for a series of transitions in the (30013)â(00001) near-infrared 12C16O2 band. These measurements were referenced to a cesium atomic clock through the use of an optical frequency comb. Combined standard uncertainties as low as 18Â kHz (6Ã10â7Â cmâ1) were achieved. Importantly, deviations as large as 5Â MHz were observed relative to the HITRAN 2008 database. These measurements were then included in a global fit of 416 CO2 mid-infrared and near-infrared measurements each of which was absolute. The resulting spectroscopic parameters provide a series of secondary frequency standards with kHz-level uncertainties across a wide frequency range and should significantly improve spectroscopic retrieval algorithms for space-based measurements of atmospheric CO2.