An empirical study on the importance of a speed-dependent Voigt line shape model for tropospheric water vapor profile remote sensing

作者：Schneider M^*; Hase F; Blavier J F; Toon G C; Leblanc T

来源：Journal of Quantitative Spectroscopy and Radiative Transfer, 2011, 112(3): 465-474.

DOI：10.1016/j.jqsrt.2010.09.008

• Water vapor
• Molecular spectroscopy
• High spectral resolution
• Line shape models
• Speed-dependent Voigt line shape
• Spectroscopic databases
• Hitran
• Atmospheric remote sensing

We use high quality ground-based solar absorption spectra measured in close coincidence with Vaisala RS92 radiosonde in situ water vapor profiles to demonstrate that a Voigt line shape model yields systematic errors in the remotely sensed tropospheric water vapor profiles. We analyse absorption signatures of 4 (H2O)-O-16 and 2 (HDO)-O-16 bands situated between 790 and 4710 cm(-1). We find that applying a speed-dependent Voigt line shape model instead of a Voigt line shape model significantly improves the agreement between the water vapor profiles obtained by the radiosondes and by infrared remote-sensing in the different bands. An optimal agreement is obtained for a Gamma(2) (relaxation rate for speed-dependence) of 6-21% of Gamma(0) (Voigt relaxation rate), which is consistent to the values derived from laboratory experiments. Our study suggests that further extensive laboratory investigations of line shape models are a key for improving the quality of modern water vapor remote sensing products.

• 出版日期2011-2