The Water Vapor Spectrum in the Region 8600–15 000 cm−1: Experimental and Theoretical Studies for a New Spectral Line Database: I. Laboratory Measurements

✍ Scribed by Roland Schermaul; Richard C.M. Learner; David A. Newnham; R.Gary Williams; John Ballard; Nikolai F. Zobov; Djedjiga Belmiloud; Jonathan Tennyson

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 205 KB
• Volume: 208
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2001.8373

✦ Synopsis

New laboratory measurements are presented for the near-infrared and visible spectrum (8600-15 000 cm -1 ) of water vapor. Spectral line parameters, principally intensities and air-broadening coefficients, are derived from Fourier transform spectroscopic measurements at high resolution (0.03 cm -1 ), a range of optical path lengths (5-513 m), and temperatures of both 252 and 296 K. Experimental line parameters are derived for 5034 assigned transitions and thorough error analysis shows parameter errors of less than 2.5% for one-third and less than 5% for over half of the lines. Calculated spectra, derived using these line parameters, reproduce the original spectra to within 2%. A comparison of the line intensities with those in the HITRAN-96 database identifies large errors in the latter with random differences that exceed a factor of two for many lines, and systematic differences between 6 and 26% depending on the water band under consideration. The recent corrections to the HITRAN database by Giver et al. (J. Quant. Spectrosc. Radiat. Transfer 66, 101-105 (2000)) do not remove these discrepancies and the differences change to 6-38%. The new data are expected to substantially increase the calculated absorption of solar energy due to water vapor in climate models.