Pressure broadening coefficients of the water vapor lines at 556.936 and 752.033 GHz

• Published in: Journal of quantitative spectroscopy & radiative transfer Vol. 109; no. 1; pp. 144 - 150
• Main Authors: Seta, Takamasa, Hoshina, Hiromichi, Kasai, Yasuko, Hosako, Iwao, Otani, Chiko, Loßow, Stefan, Urban, Joachim, Ekström, Mattias, Eriksson, Patrick, Murtagh, Donal
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2008
• Subjects: Odin/SMR; Pressure broadening; Submillimeter; Terahertz time-domain spectroscopy; Water vapor; Pressure broadening; Water vapor; Terahertz time-domain spectroscopy; Odin/SMR; Submillimeter
• ISSN: 0022-4073; 1879-1352
• DOI: 10.1016/j.jqsrt.2007.06.004

The air induced broadening coefficients of the pure rotational transitions of H 2 O at 556.936 GHz ( 1 10 ← 1 01 ) , and 752.033 GHz ( 2 11 ← 2 02 ) were measured by terahertz time-domain spectroscopy. The air broadening coefficient was determined to be 4.012 ( 30 ) MHz Torr - 1 for the 556.936 GHz line and 3.964 ( 40 ) MHz Torr - 1 for the 752.033 GHz line, respectively. The present broadening coefficients for the 556.936 GHz water line are significantly smaller than those of Markov and Krupnov [Measurements of the pressure shift of the 1(10)–1(01) water line at 556.936 GHz produced by mixtures of gases. J Mol Spect 1995:172;211–4] but relatively close to the values of the HITRAN database. The measured data may improve the accuracy of the abundance of water vapor retrieved from spectra obtained by the Odin/SMR satellite instrument. The effect on the satellite retrieval processing is discussed.