Empirical line parameters of methane from 1.1 to 2.1 μm

To provide line parameters for the near-infrared methane spectrum, 35,306 line positions and intensities at room temperature were retrieved between 6180 and 9200 cm−1, along with 4936 lines between 4800 and 5500 cm−1. For this, laboratory absorption spectra were recorded at 0.010-0.022 cm−1 resolution using the McMath-Pierce Fourier Transform Spectrometer located on Kitt Peak in Arizona. Positions were calibrated using CO transitions at 2.3 and 1.6 μm and H2O lines at 1.9 and 1.3 μm. The minimum line intensity included was 3.7×10−26 cm−1/(molecule cm−2), and the combined sum of the intensities in these two intervals was 7.085×10−20 cm−1/(molecule cm−2) at 296 (±4) K. Quantum assignments from the literature were matched for 1% of the features, and a new methane database was compiled for the near-infrared.