Hitran2020: Act (Accuracy, Completeness, Traceability)

Abstract

The HITRAN2020 database will be publicly released this year. It is a coordinated effort of experimentalists, theoreticians, atmospheric and planetary scientists who measure, calculate and validate the HITRAN data. The lists for most of the HITRAN molecules in the line-by-line section were updated in comparison with the previous compilation HITRAN2016 a . The extent of the updates ranges from updating a few lines of certain molecules to complete replacements of the lists and introducing additional isotopologues. Six new molecules (SO, CH 3 F, GeH 4 , CS 2 , CH 3 I, and NF 3 ) were also added to HITRAN. In addition, the accuracy of the parameters for major atmospheric absorbers has been increased, often featuring sub-percent uncertainties. The number of parameters was also increased significantly, now incorporating, for instance, non-Voigt line profiles for many gases; broadening by water vapor b ; update of collision-induced absorption sets c .The new edition will continue taking advantage of the modern structure and interface available at www.hitran.org and the HITRAN Application Programming Interface d . Their functionality has been extended for the new edition. This talk will provide a brief overview of HITRAN2020 e and its main improvements with respect to the previous edition.

The high-accuracy spectroscopy of H2 rovibrational transitions in the (2-0) band near 1.2 μm

“…37 reproduced in the HITRAN database. 21 We note that the uncertainty of 10% attached to the HITRAN intensity value is largely overestimated.…”

“…1 The calculated stick spectrum of the (2-0) band of H 2 . 21 Absorption lines previously measured by CRDS 7,20 are highlighted. Rotational labeling is indicated for the six transitions presently measured.…”

Mid-Infrared Generated Laser-Induced Grating Signals in Methane-Containing Gas Mixtures as Indicators of Composition, Pressure, and Temperature

“…Selective generation of LITGs in CH 4 -containing gas mixtures by narrowband radiation at ≈3.3 μm is facilitated by a large number of ro-vibrational absorption lines of P-, Q-, or Rbranches of the ν 3 fundamental band of CH 4 molecules. 49 Each of these lines is split into tetrahedral (T d ) A-, E-, or F-components corresponding to the molecules with different nuclear spins. In addition, each rotational level of the upper vibrational state, ν 3 , with the rotational quantum number J, is split by the Coriolis interaction into three sublevels with the pseudo-rotational quantum number K = J, J ± 1.…”

“…The corresponding gratings were generated at resonant excitation of CH 4 molecules via the multiplet of closely spaced four T d components of the R(4) transition at 3067.3 cm -1 . 49 The initial part of the LITG signal profiles is represented by a non-stationary contribution with characteristic oscillations.…”

Miniaturized and Portable Laser Gas Sensor for Standoff Methane Detection With Non-Cooperative Targets

“…The NIR band is a superior choice for miniaturized standoff CH 4 sensor development and application, because of the rugged and easy-to-align fiber-coupled DFB laser diode, the lowcost optical components commercially available in optical communication, and the field-tested durability. Figure S1 (Supplemental Material) displays the absorption spectrum of CH 4 in the range of 6045 to 6049 cm -1 , according to the HITRAN database, 16 with a background gas composition of 500 ppm CO 2 , 1% H 2 O and 1.8 ppm CH 4 , at T = 300 K, P = 1 atm, and L = 80 m. Analysis of the simulation results reveals a prominent absorption peak of CH 4 at 6046.95 cm -1 , with no significant interference in its vicinity. Hence, the absorption spectrum of CH 4 at 1653.73 nm (6046.95 cm -1 ) was chosen as the center spectral line of the laser.…”