Frequency-agile, rapid scanning cavity ring-down spectroscopy (FARS-CRDS) measurements of the (30012)←(00001) near-infrared carbon dioxide band

• A frequency-agile rapid scanning spectrometer was used to measure CO2.
• The near-infrared (30012)←(00001) CO2 was measured.
• The frequency axis was directly linked to an atomic clock.
• The spectra were fit with the Hartmann-Tran profile (pCqSDNGP).

We present new high accuracy measurements of the (30012)←(00001) CO2 band near 1575 nm recorded with a frequency-agile, rapid scanning cavity ring-down spectrometer. The resulting spectra were fit with the partially correlated, quadratic-speed-dependent Nelkin-Ghatak profile with line mixing. Significant differences were observed between the fitted line shape parameters and those found in existing databases, which are based upon more simplistic line profiles. Absolute transition frequencies, which were referenced to an optical frequency comb, are given, as well as the other line shape parameters needed to model this line profile. These high accuracy measurements should allow for improved atmospheric retrievals of greenhouse gas concentrations by current and future remote sensing missions.