N2 and O2 induced halfwidths and line shifts of water vapor transitions in the (301)←(000) and (221)←(000) bands

Abstract Using a complex version of Robert–Bonamy theory (CRBF), the role of the intermolecular potential in the pressure broadening of water perturbed by nitrogen and oxygen is studied. Investigation focuses on questions surrounding the convergence of calculated line widths, i.e., (i) why certain spectral lines are more sensitive than others to short-range interactions, and (ii) whether converged calculations containing short-range interactions represent an improvement over other treatments. Comparison with a large number of experimentally determined halfwidths and line shifts in the (301)←(000) and (221)←(000) bands is provided. It is found that the atom–atom component of the intermolecular potential plays an important role in determining the halfwidth and line shift. To obtain good agreement with measurement, the atom–atom potential needs to be expanded to at least eighth order for all water vapor transitions broadened by oxygen and many broadened by nitrogen.

[1]  Janet E. Jones.  On the determination of molecular fields. —II. From the equation of state of a gas , 1924 .

[2]  Jean-Michel Hartmann,et al.  Collisional broadening of rotation–vibration lines for asymmetric‐top molecules. II. H2O diode laser measurements in the 400–900 K range; calculations in the 300–2000 K range , 1987 .

[3]  M. N. Moazzen-Ahmadi.  Theoretical and Experimental Linewidth Parameters in the Rotational Spectrum of Nitrogen Dioxide , 1982 .

[4]  P. Lallemand,et al.  Influence of the use of approximate trajectories for binary collision calculations , 1978 .

[5]  S. Neshyba,et al.  Fully complex implementation of the Robert–Bonamy formalism: Half widths and line shifts of H2O broadened by N2 , 1996 .

[6]  C. F. Curtiss,et al.  Molecular Theory Of Gases And Liquids , 1954 .

[7]  Jean-Michel Hartmann,et al.  Temperature and perturber dependences of water vapor line-broadening. Experiments at 183 GHz; calculations below 1000 GHz , 1989 .

[8]  Edward V. Browell,et al.  Water-vapor line broadening and shifting by air, nitrogen, oxygen, and argon in the 720-nm wavelength region , 1989 .

[9]  K. Gubbins,et al.  Spherical harmonic expansion of the intermolecular site-site potential , 1979 .

[10]  A. Stogryn,et al.  Molecular multipole moments , 1966 .

[11]  G. Herzberg.  Molecular Spectra and Molecular Structure IV. Constants of Diatomic Molecules , 1939 .

[12]  A. Avoird,et al.  Multipole moments, polarizabilities and anisotropic long range interaction coefficients for N2 , 1980 .

[13]  W. Flygare,et al.  The molecular Zeeman effect in diamagnetic molecules and the determination of molecular magnetic moments (g values), magnetic susceptibilities, and molecular quadrupole moments , 1971 .

[14]  M. Baranger.  GENERAL IMPACT THEORY OF PRESSURE BROADENING , 1958 .

[15]  D. Hartmann.  Global Physical Climatology , 1994 .

[16]  Keith E. Gubbins,et al.  Theory of molecular fluids , 1984 .

[17]  C. Gray.  On the theory of multipole interactions , 1968 .

[18]  P. Anderson.  Pressure Broadening in the Microwave and Infra-Red Regions , 1949 .

[19]  Jean-Michel Hartmann,et al.  Collisional broadening of rotation–vibration lines for asymmetric top molecules. I. Theoretical model for both distant and close collisions , 1986 .

[20]  John S. Muenter,et al.  The dipole moment of water. II. Analysis of the vibrational dependence of the dipole moment in terms of a dipole moment function , 1991 .

[21]  D. Robert,et al.  Short range force effects in semiclassical molecular line broadening calculations , 1979 .

[22]  J. Hartmann,et al.  Collisional broadening of rotation–vibration lines for asymmetric‐top molecules. III. Self‐broadening case; application to H2O , 1987 .

[23]  C. J. Tsao,et al.  Line-widths of pressure-broadened spectral lines , 1962 .

[24]  J. Watson.  Determination of Centrifugal Distortion Coefficients of Asymmetric‐Top Molecules , 1967 .

[25]  S. Neshyba,et al.  Improved line-broadening coefficents for asymmetric rotor molecules with application to ozone lines broadened by nitrogen , 1993 .

[26]  R. A. Sack,et al.  Two-center expansion for the powers of the distance between two points , 1964 .

[27]  V. M. Devi,et al.  THE HITRAN MOLECULAR DATABASE: EDITIONS OF 1991 AND 1992 , 1992 .

[28]  G. Yamamoto,et al.  Line broadening theory of asymmetric-top molecule , 1972 .

[29]  Laurence S. Rothman,et al.  Theoretical N2-, O2-, and air-broadened halfwidths of 16O3 calculated by quantum Fourier transform theory with realistic collision dynamics , 1985 .

[30]  A. Bauer,et al.  Temperature and perturber dependences of water-vapor 380 GHz-line broadening , 1987 .

[31]  J. Hartmann,et al.  New accurate calculations of ozone line-broadening by O2 and N2 , 1988 .

[32]  J. Bouanich.  Site-site Lennard-Jones potential parameters for N2, O2, H2, CO and CO2 , 1992 .

[33]  A. Barbe,et al.  Halfwidths and line shifts of water vapor broadened by CO2: measurements and complex Robert-Bonamy formalism calculations , 1997 .

[34]  R. Kubo.  GENERALIZED CUMULANT EXPANSION METHOD , 1962 .

[35]  Robert R. Gamache,et al.  CO2-broadening of water-vapor lines , 1995 .

[36]  Yi Luo,et al.  Frequency‐dependent polarizabilities and first hyperpolarizabilities of H2O , 1993 .