The updated 2009 edition of the spectroscopic database GEISA (Gestion et Etude des Informations Spectroscopiques Atmospheriques; Management and Study of Atmospheric Spectroscopic Information) is described in this paper. GEISA is a computer-accessible system comprising three independent sub-databases devoted, respectively, to: line parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols. In this edition, 50 molecules are involved in the line parameters sub-database, including 111 isotopologues, for a total of 3,807,997 entries, in the spectral range from 10(-6) to 35,877.031 cm(-1).The successful performances of the new generation of hyperspectral sounders depend ultimately on the accuracy to which the spectroscopic parameters of the optically active atmospheric gases are known, since they constitute an essential input to the forward radiative transfer models that are used to interpret their observations. Currently, GEISA is involved in activities related to the assessment of the capabilities of IASI (Infrared Atmospheric Sounding Interferometer; http://smsc.cnes.fr/lASI/index.htm) on board the METOP European satellite through the GEISA/IASI database derived from GEISA. Since the Metop-A (http://www.eumetsat.int) launch (19 October 2006), GEISA is the reference spectroscopic database for the validation of the level-1 IASI data. Also, GEISA is involved in planetary research, i.e., modeling of Titan's atmosphere, in the comparison with observations performed by Voyager, or by ground-based telescopes, and by the instruments on board the Cassini-Huygens mission.GEISA, continuously developed and maintained at LMD (Laboratoire de Meteorologie Dynamique, France) since 1976, is implemented on the IPSL/CNRS (France) "Ether" Products and Services Centre WEB site (http://ether.ipsl.jussieu.fr), where all archived spectroscopic data can be handled through general and user friendly associated management software facilities. More than 350 researchers are registered for on line use of GEISA. (C) 2011 Elsevier Ltd. All rights reserved.

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. Published by Elsevier Science Ltd.

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.

This paper describes the status of the 2008 edition of the HITRAN molecular spectroscopic database. The new edition is the first official public release since the 2004 edition, although a number of crucial updates had been made available online since 2004. The HITRAN compilation consists of several components that serve as input for radiative-transfer calculation codes: individual line parameters for the microwave through visible spectra of molecules in the gas phase; absorption cross-sections for molecules having dense spectral features, i.e. spectra in which the individual lines are not resolved; individual line parameters and absorption cross-sections for bands in the ultraviolet; refractive indices of aerosols, tables and files of general properties associated with the database; and database management software. The line-by-line portion of the database contains spectroscopic parameters for 42 molecules including many of their isotopologues.

Using the Fourier transform spectra of the acetylene molecule recorded near 1.5-μm, the intensities of 111 lines belonging to seven hot bands of the main isotopologue 12C2H2 have been retrieved by means of a multispectrum fitting procedure. Considering the density of lines in the spectra, and the fact that the measured bands are the weakest observed, the accuracy of the measurements is around 10%. At first stage, an empirical treatment of these data has been performed, leading to the vibrational transition dipole moment squared and some Herman–Wallis coefficients. Then the measured line intensities of this work and collected ones from the literature have been treated simultaneously within the framework of the effective operator approach.

Spectroscopic data are noticeably enriched in six spectral regions of the main isotopologue 12C2H2 of the acetylene molecule, namely, in the regions around 3, 2.2, 1.9, 1.7, 1.5, and 1.4μm. Among these regions, only those at 3 and 1.5μm were already presented partly in the databases. The results of line intensity measurements, performed for the first time in the 1.4μm region, are given. Data available in the literature, or obtained in the present work, are compiled to set up line lists usable for applications in the quoted spectral regions. On the whole, 5748 new lines pertaining to 65 bands can be added to the databases.

The development of Gestion et Etude des Informations Spectroscopiques Atmospheriques (GEISA: Management and Study of Spectroscopic Information) was started over three decades at Laboratoire de Meteorologie Dynamique (LMD) in France. GEISA is a computer accessible spectroscopic database, designed to facilitate accurate forward radiative transfer calculations using a line-by-line and layer-by-layer approach. More than 350 users have been registered for on-line use of the GEISA facilities. The current 2003 edition of GEISA (GEISA-03) is a system comprising three independent sub-databases devoted respectively to: line transition parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols.Currently., GEISA is involved in activities related to the assessment of the capabilities of IASI (Infrared Atmospheric Sounding Interferometer on board of the METOP European satellite) through the GEISA/IASI database derived from GEISA.The GEISA-03 content is presented, placing emphasis on molecular species of interest for Earth and planetary atmosphere studies, with details on the updated 2008 archive underway. A critical assessment on the needs, in terms of molecular parameters archive, related with recent satellite astrophysical missions is made. Detailed information on free online GEISA and GEISA/IASI access is given at http://ara.lmd.polytechnique.fr and http://ether.ipsl.jussieu.fr. (C) 2008 Elsevier Ltd. All rights reserved.

More than 440 line positions and intensities of 8 bands of acetylene are measured in the 2.2-μm spectral region. A multispectrum fitting procedure has been applied to retrieve line parameters. The average absolute accuracy of the line parameters obtained in this work is estimated to be ±0.0005cm−1 for the line positions, and ±5% for the line intensities. Vibrational transition dipole moment and Herman–Wallis coefficients are determined for two of the studied bands. An unusual rotational dependence of the vibrational–rotational transition dipole moment of remaining bands has been found. All measured line intensities are treated simultaneously within the framework of the effective operators approach. The sets of effective dipole moment parameters obtained reproduce the observed line intensities within the experimental uncertainty.

Line intensities are measured for 546 transitions belonging to 13 bands of the main isotopologue 12C2H2 of the acetylene molecule, in the 1.5-μm spectral domain. A multispectrum fitting procedure is used to retrieve line parameters from Fourier transform spectra. Prior to this work, line intensities were known for only 4 bands in this spectral region, from the work of El Hachtouki and Vander Auwera [Absolute line intensities in acetylene: the 1.5μm region. J Mol Spectrosc 2002;216:355–62]. An excellent agreement is found with the results of these authors, showing that the accuracy of both results is likely better than 1% for the strong bands. However, the spectrum becomes very crowded when one wants to study weaker bands, so that the average accuracy of the intensities reported in the present work is 5%. From these data, vibrational transition dipole moments squared and Herman–Wallis coefficients have been determined for all the bands.

Using FT spectra (Bruker IFS 120, unapodized FWHM resolution approximate to 0.001 cm(-1)) of acetylene (C2H2)-C-12, absolute positions and intensities have been measured for about 250 lines between 2600 and 2800 cm(-1) in the v(2) + v(5)(1) and (3v(4) + v(5))(+)(0) cold bands, and in the v(1) - v(5)(1) v(3) - v(4)(1), and v(2) + (v(4) + v(5))(0)(+) - v(4)(1) hot bands. These measurements improve the accuracy of wavenumbers previously available and lead to individual line intensities for the first time in this spectral region. A multispectrum fitting procedure has been used to retrieve line parameters from five experimental spectra recorded at different pressures. The frequencies of the v(3) band of (CO2)-C-12-O-16 allowed to perform an absolute wavenumber calibration. The 5 and has been accuracy of the amount of (C2H2)-C-12 in the sample has been checked using the 3v(5)(1) cold band around 2100 cm(-1), estimated to be around +/- 2%. The average absolute accuracy of the line parameters obtained in this work has then been estimated to be +/- 0.0002 cm(-1) for line positions, and +/- 5% for line intensities. For each studied band, the vibrational transition dipole moment squared value has been determined, as also empirical Herman-Wallis coefficients. A complete line list containing positions and intensities for the five strongest bands around 3.8 mu m has been set up for atmospheric applications. (c) 2006 Elsevier Ltd. All rights reserved.

Author Institution: Laboratoire de Recherche sur la Physico-Chimie des Surfaces et Interfaces, Universite de Skikda,; BP 26, Skikda 21000, Algeria; Laboratoire de Physique Moleculaire et Applications, CNRS, case courrier 76,; Universite Pierre-et-Marie-Curie, 75252 Paris Cedex 05, France; Groupe de Spectrometrie Moleculaire et Atmospherique, CNRS, UMR 6089,; Universite de Reims-Champagne-Ardenne, Faculte des Sciences, BP 1039, 51687 Reims Cedex 2, France; Laboratoire de Photophysique Moleculaire, Unite Propre du C.N.R.S., Batiment 350,; Universite de Paris-Sud, 91405 Orsay, France, email: nathalie.picque@ppm.u-psud.fr

Author Institution: Universite Pierre-et-Marie-Curie-Paris6, Laboratoire de Dynamique, Interactions et Reactivite, CNRS,; UMR 7075, Case courrier 49, Bat F 74, 4, place Jussieu, 75252 Paris Cedex 05, France; Universite Pierre-et-Marie-Curie-Paris6, Laboratoire de Physique Moleculaire pour l'Atmosphere et l'Astrophysique,; CNRS, UMR 7092, case courrier 76, 75252 Paris Cedex 05, France; Laboratory of Theoretical Spectroscopy, Institute of Atmopheric Optics, Siberian Branch,; Russian Academy of Sciences, 1, Akademicheskii av.,634055 Tomsk, Russia; Groupe de Spectrometrie Moleculaire et Atmospherique,; Universite de Reims-Champagne-Ardenne, CNRS, BP 1039, 51687 Reims Cedex, France

More than 670 line intensities of nine perpendicular bands of acetylene are measured in the 2.5-mu m spectral region using a step-by-step interferometer. Absolute values of line intensities are obtained with an average accuracy of 5%. Vibrational transition dipole moment and Herman-Wallis coefficients are determined for each studied band. These measured line intensities, and those previously measured in the 3.8-mu m region [Jacquemart D, Lacome N, Mandin JY, Dana V, Lyulin OM, Perevalov VI. Multispectrum fitting of line parameters for (C2H2)-C-12 in the 3.8-mu m spectral region. JQSRT, submitted for publication], are treated simultaneously within the framework of the effective operators approach. The sets of effective dipole moment parameters obtained reproduce the observed line intensities within the experimental uncertainty. The good predictive ability of the modele is demonstrated. (c) 2006 Elsevier Ltd. All rights reserved.

Using Fourier transform spectra and a multispectrum fitting procedure, 271 absolute line intensities of (CO2)-C-12-O-16 have been measured around 1.6 mu m, for the three cold bands 30014-00001, 30013-00001, and 30012-00001, and for the two hot bands 31113-01101 and 31112-01101, extending from 6035 to 6380 cm(-1). Accuracies are on the average 3 and 5% for cold and hot bands, respectively. Vibrational transition dipole moments and Herman-Wallis coefficients are reported for each band. Comparisons are made with previous experimental results and with data available in the HITRAN database and the Carbon Dioxide Spectroscopic Databank (CDSD). (C) 2006 Elsevier Inc. All rights reserved.

Using Fourier-transform spectra and a multispectrum fitting procedure, 124 absolute line intensities of 12C16O2 are obtained for the cold band 30011–00001 and the hot band 01131–01101 between 6460 and 6950cm−1. Vibrational transition dipole moments squared and Herman–Wallis coefficients are reported for each band. Cross comparisons made with previous experimental results and with data available in the HITRAN and Carbon Dioxide Spectroscopic Databank (CDSD), bring some confidence on the good level of accuracy of the present results. Motivated by the demanding needs of some atmospheric experiments dedicated to the survey of the carbon cycle, an additional evaluation of potential absolute line intensity measurement limit is also performed on recently published carbon dioxide absolute line intensity independent measurements. These are obtained in two different laboratories on the bands 30013–00001 and 30012–00001 both located in the 1.6μm spectral window. It is shown that Fourier-transform experimental CO2 line intensity determination is approaching the challenging required figure of about 0.3% accuracy needed for the survey of the atmospheric carbon cycle.

The content of the current (2003) version, GEISA/IASI-03, of the computer-accessible spectroscopic database, GEISA/IASI, is described. This "system" or database is comprised of three independent spectroscopic archives, which are (a) a database of individual spectral line parameters on 14 molecules, H2O, CO2, O-3, N2O, CO, CH4, O-2, NO, SO2, NO2, HNO3, OCS, C2H2, N-2, and the related 51 isotopomers and isotopologues, representing 702,550 entries, in the spectral range 599-3001 cm(-1), (b) a database of spectral absorption cross-sections (6,572,329 entries related to six molecules, CFC-11 CFC-12, CFC-14, HCFC-22, N2O5, CCl4), and a catalogue of microphysical and optical properties (mainly, the refractive indices) of atmospheric aerosols. The modifications and improvements, which have been implemented since the earlier editions of this database, in terms of content and management, have been explained in detail. GEISA/IASI has been created with the specific purpose of assessing the capability of measurement by the IASI instrument within the designated goals of ISSWG in the frame of the CNES/EUMETSAT European Polar System preparation.All the archived data can be handled through a user-friendly associated management software, which is posted on the ARA/LMD group web site at http://ara.lmd.polytechnique.fr. (c) 2005 Elsevier Ltd. All rights reserved.

About 170 line intensities of 14 weak parallel hot bands of acetylene have been measured in the 3-μm region. Absolute values of line intensities are obtained with a mean uncertainty of 10%, except for a few lines of 3 very weak bands (uncertainty up to 20%). Vibrational transition dipole moment and Herman–Wallis coefficients have been determined for each measured band. These measured line intensities together with previously published ones (JQSRT 2005;92:239–60) have been treated simultaneously within the framework of the effective operators approach. Using only 6 effective dipole moment parameters, it was possible to reproduce the 591 measured line intensities of the 20 bands with a root mean square of the residuals equal to 4.2%.