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Flaud, J.-M.

Publications and source records attributed to Flaud, J.-M..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

Spectroscopic Parameters for Ozone and its Isotopes: Current Status, Prospects for Improvement, and the Identification of 16O16O17O and O-16O-16O-17 and O-16O-17O-16 Lines in Infrared Ground-Based and Stratospheric Solar Absorption Spectra

We describe the updates to the spectroscopic parameters of ozone and its isotopes in the 1996 HITRAN compilation. Recent published studies not included in HITRAN are also summarized. Finally, we report the identification of infrared lines of the v(sub 3) bands of O-16O-16O-17 and O-16O-17O-16 in high-resolution solar spectra recorded by stratospheric balloon-borne and ground-based Fourier transform spectrometers.

Rinsland, C. P.↗
NASA NTRS1994

Identification of the HNO3 3 nu(sub 9) - nu(sub 9) band Q branch in stratospheric solar occultation spectra

The spectroscopic identification for the HNO3 3 nu(sub 9) - nu(sub 9) band Q branch at 830.4/cm is reported based on 0.01/cm resolution solar occultation spectra of the lower stratosphere recorded by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer and a recent analysis of this band. Least-squares fits to 0.0025/cm resolution laboratory spectra in the Q branch region indicate an integrated intensity of 0.529 x 10(exp -18)/cm/mol/sq cm at 296 K for this weak band. Stratospheric HNO3 retrievals derived from the ATMOS data are consistent with this value within its estimated uncertainty of about +/- 30%. A set of spectroscopic line parameters suitable for atmospheric studies has been generated.

Perrin, A.↗
NASA NTRS1993

Stratospheric N2O5, CH4, and N2O profiles from IR solar occultation spectra

Stratospheric volume mixing ratio profiles of N2O5, CH4, and N2O have been retrieved from a set of 0.052/cm resolution (FWHM) solar occultation spectra recorded at sunrise during a balloon flight from Aire sur l'Adour, France (44 N latitude) on 12 October 1990. The N2O5 results have been derived from measurements of the integrated absorption by the 1246/cm band. Assuming a total intensity of 4.32 x 10 exp -17 cm/molecule/sq cm independent of temperature, the retrieved N2O5 volume mixing ratios in ppbv, interpolated to 2 km height spacings, are 1.64 +/- 0.49 at 37.5 km, 1.92 +/- 0.56 at 35.5 km, 2.06 +/- 0.47 at 33.5 km, 1.95 +/- 0.42 at 31.5 km, 1.60 +/- 0.33 at 29.5 km, 1.26 +/- 0.28 at 27.5 km, and 0.85 +/- 0.20 at 25.5 km. Error bars indicate the estimated 1-sigma uncertainty including the error in the total band intensity. The retrieved profiles are compared with previous measurements and photochemical model results.

Camy-Peyret, C.↗
NASA NTRS1993

The nu(sub 2) and 2nu(sub 2) - nu(sub 2) bands of N-14 (16)O2: Electron Spin-Rotation and Hyperfine Contact Resonances in the (010) Vibrational State

High-resolution Fourier transform spectra covering the 720-9-10/ cm spectral region have been used to perform a reanalysis of the 2nu(sub 2) band ((010) - (000) vibrational transition) together with the first analysis of the nu(sub 2) - nu(sub 2) hot band of nitrogen dioxide ((020)-(010) vibrational transition). The high-quality spectra show that, for numerous nu(sub 2) lines, the hyperfine structure is easily observable in the case of resonances due to the hyperfine Fermi-type operator. By performing a full treatment of the spin-rotation and of the hyperfine operators, a near line list of the nu(sub 2) band (positions and intensities) has been generated, and it is in excellent agreement with the experimental spectrum. Also, a thorough analysis of the -2nu(sub 2) nu(sub 2) hot band has been performed leading to an extended set of new (020) spin-rotation levels, These levels, together with the (100), (020), (001) spin-rotation levels deduced previously from the analysis of thenu(sub 1), 2nu(sub 2), and nu(sub 3) cold bands performed in the 6.3 - to 7.5 microns spectral range were least-squares fitted, allowing one to derive a new set of vibrational band centers and rotational. spin-rotation, and interaction constants for the {(100)(020)(001)} interacting states of N-14(16)O2.

Perrin, A.↗
NASA NTRS1993

Stratospheric N2O5, CH4, and N2O Profiles from IR Solar Occultation Spectra

Stratospheric volume mixing ratio profiles of N2O5, CH4, and N2O have been retrieved from a set of 0.052/ cm resolution (FWHM) solar occultation spectra recorded at sunrise during a balloon flight from Aire sur I'Adour, France (44 deg N latitude) on 12 October 1990. The N2O5 results have been derived from measurements of the integrated absorption by the 1246/ cm band. Assuming a total intensity of 4.32 x 10(exp 17)cm(exp -1) molecule sq cm(exp -2) independent of temperature, the retrieved N2O5 volume mixing ratios in ppbv (parts per billion by volume, 10(exp -9)), interpolated to 2 km height spacings, are 1.64 +/- 0.49 at 37.5 km, 1.92 +/- 0.56 at 35.5 km, 2.06 +/- 0.47 at 33.5 km, 1.95 +/- 0.42 at 31.5 km, 1.60 +/- 0.33 at 29.5 km, 1.26 +/- 0.28 at 27.5 km, and 0.85 +/- 0.20 at 25.5 km. Error bars indicate the estimated I-sigma uncertainty including the error in the total band intensity (+/- 20% has been assumed). The retrieved profiles are compared with previous measurements and photochemical model results.

Peyeret, C. Camy↗
NASA NTRS1992

The HITRAN molecular data base - Editions of 1991 and 1992

We describe in this paper the modifications, improvements, and enhancements to the HITRAN molecular absorption database that have occurred in the two editions of 1991 and 1992. The current database includes line parameters for 31 species and their isotopomers that are significant for terrestrial atmospheric studies. This line-by-line portion of HITRAN presently contains about 709,000 transitions between 0 and 23,000/cm and contains three molecules not present in earlier versions: COF2, SF6, and H2S. The HITRAN compilation has substantially more information on chlorofluorocarbons and other molecular species that exhibit dense spectra which are not amenable to line-by-line representation. The user access of the database has been advanced, and new media forms are now available for use on personal computers.

Rothman, Laurence S.↗
NASA NTRS1992

Improved spectroscopic line parameters for the ozone molecule

Recently available spectral O3 line parameters are summarized and progress in remote sensing based on these parameters is discussed. Particular attention is given to covering line positions, line intensities and linewidths for both the main isotopic species (O-16)3 and the isotopic variants (O-16)(O-18)(O-16) and (O-16)(O-16)(O-18).

Flaud, J.-M.↗
NASA NTRS1992

Stratospheric HNO3 measurements from 0.002/cm resolution solar occultation spectra and improved spectroscopic line parameters in the 5.8-micron region

Very-high-resolution FWHM solar-occultation spectra are investigated with a balloon-borne interferometer using revised spectroscopic line parameters for HNO3, O3, and H2O. The O3 and H2O data are evaluated to determine their capacity for interference in the HNO3 line which is studied in the nu sub 2 band at 5.8 microns. The line parameters developed with the stratospheric data are compared to data based on a HITRAN compilation as well as laboratory spectra with a 0.002/cm resolution. The line list is calculated and shown to include J and Ka transitions which improve the line parameters for HNO3 by accounting for the weaker absorption features in the stratospheric spectra. The stratospheric HNO3 profile developed analytically is compared to those based on reported measurements, and the one developed with the stratospheric solar spectra is found to be consistent with the measurements and confirm inherent measurement biases.

Goldman, A.↗
NASA NTRS1990

The 3.6-micron region of ozone - Line positions and intensities

Spectra of (O-16)3 at 1800-5400/cm, obtained at resolution 0.01/cm using the Fourier-transform spectrometer of the National Solar Observatory at Kitt Peak, are presented and analyzed; the focus is on the nu2+2nu3, nu1+nu2+nu3, and 2nu1+nu2 bands. The experimental and data-analysis procedures employed are those described by Flaud et al. (1987 and 1989), Malathy Devi et al. (1987), and Rinsland et al. (1988). The vibrational and rotational constants for the (012), (111), and (210) states are listed in a table, and the nu0 band centers for these states are given as 2726.1066/cm, 2785.2391/cm, and 2886.1781/cm, respectively.

Smith, M. A. H.↗
NASA NTRS1989

Fourier-transform spectroscopy of O3 in the 3-micron region

Fourier transform spectra of ozone have been recorded in the 2-5-micron region at a resolution of 0.01/cm. Absorption lines belonging to numerous vibration-rotation transitions have been observed in these spectra, and a detailed analysis of the band system centered at 3.6 microns has been completed.

Smith, M. A. H.↗
NASA NTRS1988

Nighttime and daytime variation of atmospheric NO2 from ground-based infrared measurements

During the period of Feb. 28 to Mar. 2, 1986, 19 high resolution atmospheric spectra have been recorded during the night using the moon or during the day using the sun as a source with the Fourier transform spectrometer at the McMath Solar telescope on Kitt Peak. The NO2 absorption peak located at 2914.65/cm has been used to derive from the spectra the total vertical column densities of atmospheric NO2. A rather rapid decrease of the NO2 amount during the night has been observed, and its daytime increase from sunrise to sunset has been confirmed. A comparison with the predictions of a photochemical model is given.

Flaud, J.-M.↗
NASA NTRS1988

The gamma 1 and gamma 3 bands of (16)O3: Line positions and intensities

Using 0.005/cm-resolution Fourier transform spectra of samples of ozone, the gamma 1 and gamma 3 bands of (16)O3 have been reanalyzed to obtain accurate line positions and an extended set of upper state rotational levels (J up to 69, K sub a up to 20). Combined with the available microwave data, these upper state rotational levels were satisfactorily fitted using a Hamiltonian which takes explicitly into account the strong Coriolis interaction affecting the rotational levels of these two interacting states. In addition, 350 relative line intensities were measured from which the rotational expansions of the transition moment operators for the gamma 1 and gamma 3 states have been deduced. Finally, a complete listing of line positions, intensities, and lower state energies of the gamma 1 and gamma 3 bands of (16)O3 has been generated.

Flaud, J.-M.↗
NASA NTRS1988

Line positions and intensities for the gamma 1 + gamma 2 and gamma 2 + gamma 3 bands of (16)O3

Using 0.005 cm-resolution Fourier transform spectra of (16)O3, generated by electric discharge from a greater than 99.98 percent pure sample of (16)O3, an extensive analysis of the gamma 1 + gamma 2 and the gamma 2 + gamma 3 bands in the 5.7 micron region was performed. The rotational energy levels of the upper (110) and (011) vibrational states of (16)O3 were reproduced within their experimental uncertainties using a Hamiltonian which takes explicitly into account the Coriolis-type interaction occurring between the rotational energy levels of both states. Improved vibrational energies and rotational and coupling constants were also derived for the (110) and (011) states. Precise transition moment constants for these two bands were deduced from analysis of 220 measured line intensities. Finally, a complete list of line positions, intensities, and lower state energies for both bands has been generated.

Devi, V. Malathy↗
NASA NTRS1987

The HITRAN database - 1986 edition

A description and summary of the latest edition of the AFGL high-resolution transmission molecular absorption database (HITRAN) parameters are presented. This new database combines the information for the seven principal atmospheric absorbers and twenty-one additional molecular species previously contained on the AFGL atmospheric absorption line parameter compilation and on the trace gas compilation. In addition to updating the parameters on earlier editions of the compilation, new parameters have been added to this edition such as the self-broadened half-width, the temperature dependence of the air-broadened half-width, and the transition probability. The database contains 348,043 entries between 0 and 17,900/cm. A FORTRAN program is now furnished to allow rapid access to the molecular transitions and for the creation of customized output. A separate file of molecular cross sections of 11 heavy molecular species, applicable for qualitative simulation of transmission and emission in the atmosphere, has also been provided.

Rothman, L. S.↗
NASA NTRS1983

AFGL atmospheric absorption line parameters compilation - 1982 edition

The latest edition of the AFGL atmospheric absorption line parameters compilation for the seven most active infrared terrestrial absorbers is described. Major modifications to the atlas for this edition include updating of water-vapor parameters from 0 to 4300 per cm, improvements to line positions for carbon dioxide, substantial modifications to the ozone bands in the middle to far infrared, and improvements to the 7- and 2.3-micron bands of methane. The atlas now contains about 181,000 rotation and vibration-rotation transitions between 0 and 17,900 per cm. The sources of the absorption parameters are summarized.

Rothman, L. S.↗