Calculations of ozone line shifting induced by N₂and O₂pressure

Abstract

Ozone line shifts by nitrogen and oxygen pressure are computed for the 1 þ 3 , 2 1 and 2 3 bands of the 5 m spectral region by a semiempirical approach. The calculated values agree with measurements better than 0.001 cm À1 atm À1 for 98% of O 3 -N 2 lines and 87% of O 3 -O 2 lines. In contrast with the water molecule case, the polarization components of the interaction potential are shown to contribute to the line shift more efficiently than the electrostatic interactions. As intermediate results, the mean dipole polarizability and the components of the polarizability tensor for the vibrational states (101), (200), and (002) of ozone molecule are determined by least-squares fitting of theoretical shifts to some experimental values. The temperature exponents for the 1 þ 3 band lines are also estimated.

First pressure shift measurement of ozone molecular lines at 9.54 μm using a tunable quantum cascade laser

“…The vibrationally dependent dipole moment and polarizability of ozone have respectively been taken from Refs. [28] and [18]. For convenience, we summarize the values of the molecular parameters used in the calculations in Table 1.…”

“…[27], except for O 3 where value for α f − α i is taken from Ref. [18] c Ref. [28] d For non-linear molecules tensorial components around principal axes are given Based on Eq.…”

“…tally [12][13][14][15][16][17] and theoretically [8,18, and references therein] mostly in the ν 1 , ν 2 , ν 1 + ν 3 , ν 1 + ν 2 + ν 3 , and 3ν 3 vibrational bands. For an extensive review of these measurements up to 1998 readers are referred to Ref.…”

Pressure broadening and shifting of vibrotational lines of atmospheric gases

“…[41] was also used in Ref. [50] to estimate ozone line shifts by N 2 and O 2 pressure in the ν 1 + ν 3 , 2ν 1 , and 2ν 3 bands. The calculated shifts agree with measurements within 0.001 cm -1 atm -1 for 98% of O 3 -N 2 lines and for 87% of O 3 -O 2 lines.…”

“…Table 4.13. Semi-empirical and experimental [45] O 3 line-shift coefficients (in 10 -3 cm -1 atm -1 ) and temperature exponents n for the ν 1 +ν 3 band (lines used for fitting are marked with an asterisk) [50]. Reproduced with permission.…”