کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5429320 | 1397346 | 2011 | 13 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Assessment of the consistency of H2O line intensities over the near-infrared using sun-pointing ground-based Fourier transform spectroscopy Assessment of the consistency of H2O line intensities over the near-infrared using sun-pointing ground-based Fourier transform spectroscopy](/preview/png/5429320.png)
We report on the consistency of water vapour line intensities in selected spectral regions between 800-12,000Â cmâ1 under atmospheric conditions using sun-pointing Fourier transform infrared spectroscopy. Measurements were made across a number of days at both a low and high altitude field site, sampling a relatively moist and relatively dry atmosphere. Our data suggests that across most of the 800-12,000Â cmâ1 spectral region water vapour line intensities in recent spectral line databases are generally consistent with what was observed. However, we find that HITRAN-2008 water vapour line intensities are systematically lower by up to 20% in the 8000-9200Â cmâ1 spectral interval relative to other spectral regions. This discrepancy is essentially removed when two new linelists (UCL08, a compilation of linelists and ab-initio calculations, and one based on recent laboratory measurements by Oudot et al. (2010) [10] in the 8000-9200Â cmâ1 spectral region) are used. This strongly suggests that the H2O line strengths in the HITRAN-2008 database are indeed underestimated in this spectral region and in need of revision. The calculated global-mean clear-sky absorption of solar radiation is increased by about 0.3Â WÂ mâ2 when using either the UCL08 or Oudot line parameters in the 8000-9200Â cmâ1 region, instead of HITRAN-2008. We also found that the effect of isotopic fractionation of HDO is evident in the 2500-2900Â cmâ1 region in the observations.
⺠We examine the consistency of H2O line intensities in the 800-12,000 cmâ1 spectral region. ⺠In the 8000-9200 cmâ1 spectral region, we find that the HITRAN-2008H2O line intensities are too weak. ⺠This discrepancy is essentially removed when two new linelists (UCL08 or Oudot) are considered. ⺠The effect of the new linelists on the global-mean clear-sky absorption is calculated. ⺠Compared to HITRAN-2008, the absorption of solar radiation is increased by about 0.3 W mâ2.
Journal: Journal of Quantitative Spectroscopy and Radiative Transfer - Volume 112, Issue 14, September 2011, Pages 2268-2280