TY - JOUR
T1 - Vibrational dependence, temperature dependence, and prediction of line shape parameters for the H2O-H2 collision system
AU - Gamache, Robert
AU - Vispoel, Bastien
AU - Renaud, Candice L.
AU - Cleghorn, Kara
AU - Hartmann, Léna
N1 - Funding Information:
The authors are pleased to acknowledge support of this research by the National Science Foundation through Grant No. AGS-1622676 . Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Publisher Copyright:
© 2019
PY - 2019/7/1
Y1 - 2019/7/1
N2 - In a recent work on line shape parameters for the H
2 O-H
2 [Renaud et al., Icarus, 306,275, 2018] it was shown that this far off-resonance collision system displays strong vibrational dependence. In Renaud et al., calculations were made for bands with one bend or stretch (symmetric or antisymmetric) vibrational quanta exchanged. Water is seen throughout the universe under a vast range of conditions. The needs of the spectroscopic and astrophysics communities include data for water vapor transitions with multiple quanta exchanged. In this work, calculations were made using the Modified Complex Robert-Bonamy (MCRB) formalism for 0–4 vibrational quanta exchanged in the ν
1 , ν
2 , and ν
3 bands, and the 3ν
1 + ν
3 band at 13 temperatures from 200 to 3000 K: calculations for more than 100,000 transitions. From these data, the vibrational dependence of the half-width, line shift, and their temperature dependence are studied as a function of rotational transition. The results show a strong and unusual vibrational dependence. The data were used to develop a prediction routine, which is based on theory [Gamache and Hartmann, JQSRT, 83, 119, 2004] rather than ad hoc fitting to a polynomial or other forms. The resulting prediction algorithm gives line shape parameters with much lower uncertainty compared to those from J″ average values or polynomial methods. A line file, based on HITRAN2016, was created for remote sensing applications that study H
2 O in hydrogen-rich atmospheres.
AB - In a recent work on line shape parameters for the H
2 O-H
2 [Renaud et al., Icarus, 306,275, 2018] it was shown that this far off-resonance collision system displays strong vibrational dependence. In Renaud et al., calculations were made for bands with one bend or stretch (symmetric or antisymmetric) vibrational quanta exchanged. Water is seen throughout the universe under a vast range of conditions. The needs of the spectroscopic and astrophysics communities include data for water vapor transitions with multiple quanta exchanged. In this work, calculations were made using the Modified Complex Robert-Bonamy (MCRB) formalism for 0–4 vibrational quanta exchanged in the ν
1 , ν
2 , and ν
3 bands, and the 3ν
1 + ν
3 band at 13 temperatures from 200 to 3000 K: calculations for more than 100,000 transitions. From these data, the vibrational dependence of the half-width, line shift, and their temperature dependence are studied as a function of rotational transition. The results show a strong and unusual vibrational dependence. The data were used to develop a prediction routine, which is based on theory [Gamache and Hartmann, JQSRT, 83, 119, 2004] rather than ad hoc fitting to a polynomial or other forms. The resulting prediction algorithm gives line shape parameters with much lower uncertainty compared to those from J″ average values or polynomial methods. A line file, based on HITRAN2016, was created for remote sensing applications that study H
2 O in hydrogen-rich atmospheres.
UR - http://www.scopus.com/inward/record.url?scp=85063049823&partnerID=8YFLogxK
U2 - 10.1016/j.icarus.2019.02.011
DO - 10.1016/j.icarus.2019.02.011
M3 - Article
SN - 0019-1035
VL - 326
SP - 186
EP - 196
JO - Icarus
JF - Icarus
ER -