Search

The article focuses on a study on water vapour spectroscopy and its impact on the ratio of heavy water (HDO) and water (H2O) in Scanning Imaging Absorption spectrometer for Atmospheric Cartography (SCIAMACHY). In the study,the impact of updated water spectroscopy is tested on total column retrievals of high-resolution Fourier-Transform Spectrometers (FTS). It shows negative shift in the HDO/H2O ratio for both the SCHIAMACHY and FTS measurements.

Abstract: This paper is the second of a series that reports results on the measurements of the absorption cross section of SO2 in the UV/visible region at high resolution and that investigates high temperatures in support to planetary applications. Absorption cross sections of SO2 have been obtained in the 29000–44000cm−1 spectral range (227–345nm) with a Fourier transform spectrometer at a resolution of 2cm−1 (0.4500cm MOPD and boxcar apodisation). Pure SO2 samples were used and measurements were performed at room temperature (298K) as well as at 318, 338 and 358K. Temperature effects in this spectral region are investigated and are favorably compared to existing studies in the literature. Comparison of the absorption cross section at room temperature shows good agreement in intensity with most of the literature data, but shows that most of the latter suffer from inaccurate wavelength scale definition. Moreover, literature data are often given only on restricted spectral intervals. Combined with the data described in the first part of this series of papers on SO2, this new data set offers the considerable advantage of covering the large spectral interval extending from 24000 to 44000cm−1 (227–420nm), at the four temperatures investigated. [Copyright &y& Elsevier]

Abstract: Absorption cross sections of SO2 have been obtained in the 24000–29000cm−1 spectral range (345–420nm) with a Fourier transform spectrometer at a resolution of 2cm−1. Pure SO2 samples were used and measurements were performed at room temperature (298K) as well as at 318, 338 and 358K. This is the first time that temperature effects in this spectral region are reported and investigated. This paper is the first of a series that will report on measurements of the absorption cross section of SO2 in the UV/visible region at a higher than previously reported resolution and that will investigate temperature effects in support of tropospheric, stratospheric and astrophysical or planetary applications. [Copyright &y& Elsevier]

Abstract: Absorption spectra of HDO/D2O mixtures recorded in the 5600–8800cm−1 region with a total pressure of water from 13 up to 18hPa and an absorption path length of 600m have been analyzed in order to obtain new spectroscopic data for HD18O and D2 18O. In spite of the low natural 18O concentration (about 2×10−3 with respect to the 16O one), about 1100 transitions belonging to HD18O and more than 280 transitions belonging to D2 18O have been assigned. Most of the D2 18O transitions belong to the ν 1+ν 2+ν 3 and 2ν 1+ν 3 bands. Sets of energy levels for seven vibrational states of D2 18O and four states of HD18O are reported for the first time. The comparison of the experimental data with the calculated values based on Partridge–Schwenke global variational calculations is discussed. [ABSTRACT FROM AUTHOR]

Abstract: All available transitions from microwave to visible region (0.2–12 105cm−1) of the HD18O molecule were collected and tested using the RITZ computer code. Literature data were completed by transitions assigned to HD18O in long path Fourier transform absorption spectra of the H2O, HDO and D2O gas mixtures with natural abundance of oxygen-18. In addition about 40 unassigned lines between 4200 and 6600cm−1 of our previous water study associated with the HD18O molecule have been found and assigned. The new long path absorption spectra of the HDO and D2O mixtures allow us to observe about 1000 transitions of HD18O in the 6125–10720cm−1 spectral region. These data have been critically analyzed and used to obtain the most complete and precise set of the experimental energy levels of this molecule. [Copyright &y& Elsevier]

Abstract: The absorption spectrum of dideuterated water, D2O, has been recorded between 8800 and 9520cm−1 by intracavity laser absorption spectroscopy (ICLAS) based on a vertical external cavity system emitting laser (VeCSEL) and by high sensitivity Fourier Transform spectroscopy. The combined analysis of the spectra has allowed attributing 1223 transitions to the D2O species. The spectrum assignment was performed on the basis of the recent results of variational calculations based on an optimized potential energy surface of D2O. A set of 687 energy levels was derived from transitions assigned to eight upper vibrational states, 577 of them being reported for the first time. A detailed line list has been generated. The line intensities were retrieved mainly from the FTS spectrum and the absolute integrated intensities of the 2v 1 + v 2 + v 3 and the v 2 +3v 3 bands dominating the spectrum have been determined. [Copyright &y& Elsevier]