Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers. Visit https://espo.nasa.gov for information about our current projects.


Absolute CO2 transition frequencies at the kHz-level from 1.6 to 7.8 um

Long, D. A., G.-W. Truong, and J. Hodges (2013), Absolute CO2 transition frequencies at the kHz-level from 1.6 to 7.8 um, J. Quant. Spectrosc. Radiat. Transfer, doi:10.1016/j.jqsrt.2013.07.001.

Absolute transition frequencies were measured for a series of transitions in the (30013)←(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 18 kHz (6 × 10 -7 cm -1) were achieved. Importantly, deviations as large as 5 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. 35 37

PDF of Publication: 
Download from publisher's website.
Research Program: 
Upper Atmosphere Research Program (UARP)