Abstract
The strong and sharp pQ 3 subbranch of the ν 7 band of ethane near 2976.8 cm -1 is relatively free of interfering lines of methane, water and ozone and has been utilized as the signature of ethane for atmospheric monitoring. This subbranch is unresolvable at the Doppler limit, even at low temperature. However, the rotational structure and torsional splittings have been obtained by subDoppler molecular-beam spectroscopy, along with the air-broadening coefficients and their temperature dependence, so that the fundamental band subbranch can be well characterized, apart from minor perturbations evident at high J. This still leaves a significant fraction of the observed structure and intensity in this region unassigned. The strong temperature dependence of this extraneous structure enables us to attribute it to torsional hot bands, which improves the quantitative estimates of atmospheric ethane. We also discuss various approximations to the ethane partition function, accounting for the highly anharmonic torsional mode, needed for the accurate scaling of the intensities over the wide range of atmospheric temperatures.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Quantitative Spectroscopy and Radiative Transfer
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
