An intercomparison of laboratory measurements of absorption cross-sections and integrated absorption intensities for HCFC-22

New and improved infrared absorption cross sections for chlorodifluoromethane (HCFC-22)

“…During the experimental work, evidence was found for chlorodifluoromethane adsorption in the vacuum line and on the cell walls, resulting in its partial pressure during each measurement differing from the initial, measured value, although there was no evidence for this partial pressure changing over the course of a scan. This confirms previous observations made during the Spectroscopy and Warming potentials of Atmospheric Greenhouse Gases (SWAGG) project, which focused only on spectroscopic measurements for radiative forcing and global warming potentials rather than for remote sensing (Ballard et al, 2000). Due to this adsorption, the initial cross sections derived from Eq.…”

Absolute Intensities Measurements in the ν4 + ν5 Band of 12C2H2: Analysis of Herman–Wallis Effects and Forbidden Transitions

“…The dominant contribution to systematic errors was found to come from offsets in the 0% transmittance level and nonlinearities in the response of the HgCdTe detector. Investigation of these sources of systematic error (23) showed that, in the present experimental conditions, the corresponding uncertainty on the measured line intensities is smaller than 1%. We thus estimate that the accuracy of the line intensities measured is better than 2% at all JЉ values.…”

“…[19] and [20] using the values of the parameters involved given in Eqs. [21] and [23] Table 1) and the error bars the corresponding uncertainty (3). The dotted line shows the J-dependence predicted by ᐉ-type resonance alone as described in the section "ᐉ-type resonance" (see text), while the solid line represents the Herman-Wallis behavior predicted by ᐉ-type resonance and Coriolis coupling, calculated using Eqs.…”

Anharmonic theoretical simulations of infrared spectra of halogenated organic compounds

“…Indeed, the macroscopic radiation and atmospheric models, employed to understand the atmospheric chemistry as well as to model the Earth's atmosphere and its evolution, need as an input a detailed dataset. [8][9][10] Within this framework, infrared (IR) spectroscopy plays a primary role, [11][12][13][14][15][16][17][18][19][20][21] as it can provide accurate values of the relevant spectroscopic data, such as band positions and absorption cross sections. With these premises, it is not surprising that the last years have seen a renewed interest in the spectroscopic studies of halogenated organic compounds, motivated not only by their role as air pollutants, but also because these investigations are useful to improve the modeling of the atmospheric chemistry of these compounds.…”