Shifting and broadening parameters of the water vapor 183-GHz line (313–220) by H2O, O2, N2, CO2, H2, He, Ne, Ar, and Kr at room temperature

CO2-broadened water in the pure rotation and ν2 fundamental regions

“…Thus, no conclusion could be reached about vibrational dependence using experimental data of CO 2 -broadened water. We note that only one pressure shift has been measured for the rotational band; Golubiatnikov et al [13] reported a value of À0.0237 cm À1 atm À1 for the (3 1 3 ‹ 2 2 0 ) transition which is in excellent agreement with the measured value in m 2 of À0.0238 (47) cm À1 atm À1 . Our measured shift value for (2 2 0 ‹ 3 1 3 ) is 0.0258 (97) cm À1 atm À1 .…”

“…Unfortunately, the present CO 2 -broadened water measurements of strong, allowed, perpendicular transitions in m 2 were in common with only one rotational transition from Golubiatnikov et al [13], 1.3 lm [17]. The number is very limited because one study reported weak transitions in the wings of bands [15,18] while the other two investigations measured small spectral intervals with diode laser spectrometers [16,17].…”

“…The newer studies [13][14][15][16][17] measured widths to only 80, by reporting one perpendicular type transition in the rotational region [13] and four m 2 lines at 1539 and 1652 cm À1 [14], and mostly parallel band transitions at 3963-4181 cm À1 [15], 7117-7186 cm À1 [16] and 7226-7233 cm À1 [17]; the pressure shifts were measured for 34 transitions [13,14,18].…”

“…HWHM) are in units of cm À1 atm À1 at 300 K. The other measurements are from: Golubiatnikov et al[13]; Gamache et al[15]; Langolis et al[17] and Nagali et al[16].…”

Uncertainty of atmospheric microwave absorption model: impact on ground-based radiometer simulations and retrievals

“…Since 2003, the model includes the pressure line shift mechanism investigated by Tretyakov et al (2003) andGolubiatnikov et al (2005). For the 22.23 and 183.31 GHz absorption lines, the only two relevant for the frequency range under study here, the main modifications are the adoption of the air-broadened line widths determined in Payne et al (2008) using groundbased radiometric measurements, leading to -5.1% and +4.5% line-width change, respectively.…”