K. Yoshino

THE HITRAN MOLECULAR SPECTROSCOPIC DATABASE AND HAWKS (HITRAN ATMOSPHERIC WORKSTATION): 1996 EDITION

Since its first publication in 1973, the HITRAN molecular spectroscopic database has been recognized as the international standard for providing the necessary fundamental spectroscopic parameters for diverse atmospheric and laboratory transmission and radiance calculations. There have been periodic editions of HITRAN over the past decades as the database has been expanded and improved with respect to the molecular species and spectral range covered, the number of parameters included, and the accuracy of this information. The 1996 edition not only includes the customary line-by-line transition parameters familiar to HITRAN users, but also cross-section data, aerosol indices of refraction, software to filter and manipulate the data, and documentation. This paper describes the data and features that have been added or replaced since the previous edition of HITRAN. We also cite instances of critical data that are forthcoming.

The HITRAN molecular spectroscopic database: edition of 2000 including updates through 2001

This paper describes the status circa 2001, of the HITRAN compilation that comprises the public edition available through 2001. The HITRAN compilation consists of several components useful for radiative transfer calculation codes: high-resolution spectroscopic parameters of molecules in the gas phase, absorption cross-sections for molecules with very dense spectral features, aerosol refractive indices, ultraviolet line-by-line parameters and absorption cross-sections, and associated database management software. The line-by-line portion of the database contains spectroscopic parameters for 38 molecules and their isotopologues and isotopomers suitable for calculating atmospheric transmission and radiance properties. Many more molecular species are presented in the infrared cross-section data than in the previous edition, especially the chlorofluorocarbons and their replacement gases. There is now sufficient representation so that quasi-quantitative simulations can be obtained with the standard radiance codes. In addition to the description and justification of new or modified data that have been incorporated since the last edition of HITRAN (1996), future modifications are indicated for cases considered to have a significant impact on remote-sensing experiments

The HITRAN molecular spectroscopic database and HAWKS (HITRAN atmospheric workstation)

Nineteen ninety-eight marks the 25th anniversary of the release of the first HITRAN database. HITRAN is recognized as the international standard of the fundamental spectroscopic parameters for diverse atmospheric and laboratory transmission and radiance calculations. There have been periodic editions of HITRAN over the past decades as the database has been expanded and improved with respect to the molecular species and spectral range covered, the number of parameters included, and the accuracy of this information. The 1996 edition not only includes the customary line-by-line transition parameters familiar to HITRAN users, but also cross-section data, aerosol indices of refraction, software to filter and manipulate the data, and documentation. This paper describes the data and features that have been added or replaced since the previous edition of HITRAN. We also cite instances of critical data that is forthcoming. A new release is planned for 1998.

High resolution absorption cross section measurements and band oscillator strengths of the (1, 0)−(12, 0) Schumann-Runge bands of O2

Abstract Cross sections of O 2 at 300 K have been obtained from photoabsorption measurements at various pressures throughout the wavelength region 179.3–201.5 nm with a 6.65 m photoelectric scanning spectrometer equipped with a 2400 lines mm −1 grating and having an instrumental width (FWHM) of 0.0013 nm. The measured absorption cross sections of the Schumann-Runge bands (12, 0) through (1, 0) in this wavelength region are absolute, i.e., independent of the instrumental width, a result not achieved previously. The measured cross sections are presented graphically and are available at wavenumber intervals of > sim; 0.1 cm −1 as numerical complications stored on magnetic tape from the National Space Science Data Center, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, U.S.A. Band oscillator strengths of the (12, 0) through (1, 0) bands have been determined by direct numerical integration of the measured cross sections.

Vacuum ultraviolet absorption spectra of the van der Waals molecules Kr2 and ArKr

The vacuum ultraviolet absorption spectrum of the van der Waals dimer Kr2 has been photographed in the region 1050–1260 A by a 6.65 m spectrograph with the argon continuum as background source. Eight band systems, four well‐developed and four rather fragmented, are observed. Vibronic analyses of the former four systems reveal that their upper states are correlated to separated atom limits in which one Kr atom is excited to various levels of configuration 4p55s. Upper molecular state designations and dissociation limits are discussed. The four fragmented band systems are energetically close to various KrI levels of configuration 4p55p. A similar study of a mixture of argon and krypton yields five groups of diffuse bands attributed to ArKr; two of these band groups are close to KrI resonance lines. The ground electronic state of Kr2 supports 16 bound vibrational levels of which nine (ν″ = 0–8) are involved in the observed vibronic structure and the other seven inferred from an extrapolation procedure based ...

Vacuum ultraviolet absorption spectrum of the van der Waals molecule Xe2. I. Ground state vibrational structure, potential well depth, and shape

The vacuum ultraviolet absorption spectrum of the van der Waals molecule Xe2 has been photographed at high resolution. Ground state vibrational spacings ΔG(v+½) with v = 0–9 have been extracted from the vibronic structure of two electronic transitions. An extrapolation procedure based on an assumed inverse sixth power long‐range potential reveals that the ground electronic state of Xe2 supports 25 or 26 bound vibrational levels. Spectroscopic values for the well depth, 195.5 cm−1, and zero‐point energy, 10.4 cm−1, are compared to results from recent molecular beam scattering experiments. The shapes of the spectroscopic and scattering potentials are examined by means of Rydberg‐Klein‐Rees plots of well depth vs well width.

Improved absorption cross-sections of oxygen in the wavelength region 205-240 nm of the Herzberg continuum

Abstract The laboratory values of the Herzberg continuum absorption cross-section of oxygen at room temperature from Cheung et al . (1986, Planet. Space Sci. 34 , 1007), Jenouvrier et al . (1986a, Planet. Space Sci. 34 , 253) and Jenouvrier et al . (1986, J. quant. Spectrosc. radiat. Transfer 36 , 349) have been compared and re-analyzed. There is no discrepancy between the absolute values of these two sets of independent measurements. These values have been combined together in a linear least-squares fit to obtain improved values of the Herzberg continuum cross-section of oxygen at room temperature throughout the wavelength region 205–240 nm. Agreement with in situ and other laboratory measurements is discussed.

High resolution absorption cross-section measurements of ozone at 195 K in the wavelength region 240–350 nm

Cross-sections of the Hartley-Huggins bands of 03 at the temperature 195 K have been obtained from photoabsorption measurements at column densities in the range 2 × 1017−1 × 1021 cm−2 throughout the wavelength region 240–350 nm with a 6.65 m photoelectric scanning spectrometer equipped with a 2400 lines mm−1 grating and operated at an instrumental width (FWHM) of 0.003 nm. The assumptions made in putting the measured relative cross-sections on an absolute basis are discussed. Fine structure in the cross-section observed in the Huggins bands is illustrated in the region 323–327 nm where shallow features of width 0.01–0.02 nm occur superposed on a stronger apparent continuum exhibiting broader wavy structure.

Atlas of the Schumann–Runge Absorption Bands of O2 in the Wavelength Region 175–205 nm

After a critical summary of previous wavelength measurements and rotational line assignments of the Schumann–Runge absorption bands of O2, the results of the present study performed at high resolution with a 6.65 m vacuum spectrograph are given. These include (a) an atlas of the Schumann–Runge absorption bands of O2 at 300 K showing detailed rotational line assignments in the wavelength region 175–205 nm containing the bands (v′,0) with v′=0–21 and (v′,1) with v′=2–16; (b) tables of wave numbers measured for rotationally assigned principal branch lines belonging to the bands (v′,0) with v′=0–17 and (v′,1) with v′=2–17; (c) a table of measured wave numbers of lines in the region near the dissociation limit where many unassigned lines exist; (d) a table of wave numbers calculated for satellite and forbidden lines belonging to the bands (9,0)–(17,0) together with the few values obtained from our measurements; and (e) a table of term values for the upper state B 3Σ−u vibration–rotation levels with v′=9–17 cal...

Absorption Spectrum of the Argon Atom in the Vacuum-Ultraviolet Region

The absorption spectrum of atomic argon below 1000 A has been investigated with a 6.65-m vacuum spectrograph and with the helium continuum for background. The expected five ns and nd Rydberg series have been extended as far as lines with n about 50 and greater. The ionization energies obtained are 127 109.9±0.1 cm−1 and 128 541.8±0.3 cm−1 for P2320 and P2120 states of Ar ii, respectively. Strong interactions between nd and nd′ series are observed as perturbations and autoionizations. Six additional (weak) Rydberg series are identified as electric-quadrupole transitions to 3p5np and 3p5nf levels.