Improving spectroscopic line parameters by means of atmospheric spectra: Theory and example for water vapor and solar absorption spectra

Abstract Current atmospheric remote sensing experiments measuring high resolution spectra apply instruments of similar quality as the laboratory experiments that are especially equipped to derive spectroscopic parameters. We propose a method that uses high quality atmospheric spectra to improve the spectroscopic parameterization. It is an optimal estimation method that applies the uncertainty ranges given in current spectroscopic databases as a priori covariance and the residuals between the simulated and measured atmospheric spectra as new measurements. We test the method by updating the current HITRAN parameters of 49 mid-infrared water vapor lines (situated in 15 spectral windows between 795 and 1330 cm - 1 ) by the information present in high quality ground-based Fourier transform infra-red (FTIR) spectra. We show that the application of a speed dependent Voigt line shape model is important. The updated water vapor parameterization, compared to the original one, leads to lower residuals, larger measurement information content, and better agreement between remotely sensed and coincident in situ water vapor profiles. Using the new line parameterization, a state-of-the-art ground-based FTIR system is able to monitor upper tropospheric water vapor amounts and middle/upper tropospheric HDO / H 2 O ratios.

[1]  Holger Vömel,et al.  Radiation Dry Bias of the Vaisala RS92 Humidity Sensor , 2007 .

[2]  B. Soden,et al.  WATER VAPOR FEEDBACK AND GLOBAL WARMING 1 , 2003 .

[3]  J. Cooper,et al.  CORRELATION EFFECTS IN THE THEORY OF COMBINED DOPPLER AND PRESSURE BROADENING-I. CLASSICAL THEORY* , 1974 .

[4]  T. Blumenstock,et al.  Comparison of ground-based Brewer and FTIR total O 3 monitoring techniques , 2008 .

[5]  M. Mazière,et al.  Retrieval and characterization of ozone profiles from solar infrared spectra at the Jungfraujoch , 2002 .

[6]  Paul R. Berman,et al.  Speed-dependent collisional width and shift parameters in spectral profiles , 1972 .

[7]  Gang Li,et al.  The HITRAN 2008 molecular spectroscopic database , 2005 .

[8]  T. Blumenstock,et al.  Quality assessment of O 3 profiles measured by a state-of-the-art ground-based FTIR observing system , 2008 .

[9]  Laurence S. Rothman,et al.  Current updates of the water-vapor line list in HITRAN: A new “Diet” for air-broadened half-widths , 2007 .

[10]  K. Strong,et al.  Effects of vertical grid discretization in infrared transmission modeling , 2008 .

[11]  L. Galatry,et al.  Simultaneous Effect of Doppler and Foreign Gas Broadening on Spectral Lines , 1961 .

[12]  T. Blumenstock,et al.  Analysis of the instrumental line shape of high-resolution fourier transform IR spectrometers with gas cell measurements and new retrieval software. , 1999, Applied optics.

[13]  Peter F. Bernath,et al.  Speed-dependent Voigt profile for water vapor in infrared remote sensing applications , 2007 .

[14]  C. Rinsland,et al.  Intercomparison of retrieval codes used for the analysis of high-resolution, ground-based FTIR measurements , 2004 .

[15]  R. P. Lowe,et al.  Atmospheric Chemistry Experiment (ACE): Mission overview. , 2005 .

[16]  K. Shine,et al.  Assessment of the consistency of near‐infrared water vapor line intensities using high‐spectral‐resolution ground‐based Fourier transform measurements of solar radiation , 2006 .

[17]  R. Dicke.  The effect of collisions upon the Doppler width of spectral lines , 1953 .

[18]  Franz Schreier,et al.  The 2003 edition of the GEISA/IASI spectroscopic database , 2005 .

[19]  K. Smith,et al.  Line parameter validation using ground-based solar occultation measurements: Water vapor—A case study , 2007 .

[20]  T. Blumenstock,et al.  Observation of unusual chlorine activation by ground-based infrared and microwave spectroscopy in the late Arctic winter 2000/01 , 2005 .

[21]  Frank Hase,et al.  Ground-based remote sensing of HDO/H 2 O ratio profiles: introduction and validation of an innovative retrieval approach , 2006 .

[22]  Matthias Schneider,et al.  Water vapour profiles by ground-based FTIR spectroscopy: study for an optimised retrieval and its validation , 2005 .

[23]  Clive D Rodgers,et al.  Inverse Methods for Atmospheric Sounding: Theory and Practice , 2000 .

[24]  T. Clarmann,et al.  MIPAS: an instrument for atmospheric and climate research , 2007 .