LINE ASSIGNMENTS AND POSITION MEASUREMENTS IN SEVERAL WEAK $CO_{2}$ BANDS BETWEEN $4590 cm^{-1}$ AND $7930cm^{-1}$

Abstract

A substantial set of $CO_{2}$ spectra from 4500 to $12000 cm^{-1}$ has been obtained at Ames with 1500 m path length using a Bomem DA8 FTS. The signal/noise was improved compared to prior spectra obtained in this labatory by including a filter wheel limiting the band-pass of each spectrum to several hundred $cm^{-1}$. We have measured positions of lines in several weak bands not previously resolved in laboratory spectra. Using our positions and assignments of lines of the Q branch of the 31103-00001 vibrational band at $4591 cm^{-1}$, we have redetermined the rotational constants for the 31103f levels. Q-branch lines of this band were previously observed, but missassigned, in Venus spectra by Mandin (J. Mol. Spec. 67, 304, 1977). The current HITRAN values of the rotational constants for this level are incorrect due to the Q-branch missassignments. Our prior measurements of the 21122-00001 vibrational band at $7901 cm^{-1}$s were limited to Q- and R-branch lines; with the improved signal/noise of these new spectra we have now measured lines in the weaker P branch. The 21122 $(G_{v}=7901.48 cm^{-1})$ levels are known to be perturbed by the 3211 $(G_{v}=7897.57 cm^{-1})$ levels; our new ``irect Numerical Diagonalization (J.Q.S.R.T. 48, 763, 1992)'' calculations predict that high-J lines of the forbidden 32211-00001 vibrational band ``borrow'' intensity from the corresponding transition of the 21122-00001 band. We have identified such Q- and R-branch transitions of the 32211-00001 band from $26 \leq J'' \leq 44$, based on our position measurements of lines in the 32211-02201 band at $6562 cm^{-1}$.