Non local thermodynamic equilibrium (LTE) atmospheric limb emission at 4.6 μm: 2. An analysis of the daytime wideband radiances as measured by UARS improved stratospheric and mesospheric sounder

Abstract

Abstract. An analysis of the measurements taken by the improved stratospheric and mesospheric sounder (ISAMS) in its carbon monoxide wideband channel around

Vibrational‐vibrational and vibrational‐thermal energy transfers of CO2 with N2 from MIPAS high‐resolution limb spectra

“…SAMS and ISAMS measurements near 4.3 μm are less sensitive to these rates. López‐Puertas and Taylor [] and López‐Puertas et al [, ] analyzed those observations including values of 2·10 −11 and 2.4·10 −12 cm 3 s −1 . These values were based on the measurements of Jacobs et al [] of 2·10 −11 cm 3 s −1 for the redistribution between the 10001 and 10002 levels, and on the results of Finzi and Moore [] who found that the redistribution of the v 1 and v 2 quanta is independent of the vibrational excitation of the v 3 mode.…”

“…The same rate was used by Funke et al []. Only the analysis of ISAMS measurements [ López‐Puertas et al , , ] suggested that a factor between 0.8 and 1.0 times the rate of Inoue and Tsuchiya [] was consistent with ISAMS radiances taken at a SZA lower and higher than 60°, respectively. In our analysis we use the fit k v v ,0 =4.64·10 −13 (300/ T ) 0.64 to the measurements of Inoue and Tsuchiya [], which is very similar to the usual form of (see Figure a).…”

“…As for k v v ,1 , this rate has also been taken equal to that of the fundamental band, k v v ,0 , in all previous studies, including the analysis of the SPIRE emission near 2.7 μm [ Sharma and Wintersteiner , ], except for SAMS and ISAMS. López‐Puertas et al [, ] found, as for k v v ,0 , that a value between 0.8 and 1.0 times that of Inoue and Tsuchiya [] fitted better SAMS and ISAMS measurements. Note that López‐Puertas and Taylor [] derived a rate twice that value but a subsequent analysis showed a factor of 0.8–1 [ López‐Puertas et al , , ].…”

“…López‐Puertas et al [, ] found, as for k v v ,0 , that a value between 0.8 and 1.0 times that of Inoue and Tsuchiya [] fitted better SAMS and ISAMS measurements. Note that López‐Puertas and Taylor [] derived a rate twice that value but a subsequent analysis showed a factor of 0.8–1 [ López‐Puertas et al , , ]. The value derived here is significantly larger at temperatures smaller than 300 K, ranging from a factor of 1 to 1.5 from 300 K to 130 K, which is caused by the stronger temperature dependence retrieved here (compare red and black dashed lines in Figure a).…”

Observations and Modeling of Atmospheric Radiance Structure

“…There are other uncertainties to consider in a retrieval under non-LTE conditions. Specifically, C0 2 is apparently not well mixed above 75 km [Lopez-Puertas et al, 1998b]. Uncertainties in CO2 will manifest themselves as uncertainties in the retrieved mesospheric temperature.…”