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This paper describes the 2020 release of the GEISA database (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Atmospheric Spectroscopic Information), developed and maintained at LMD since 1974. GEISA is the reference database for several current or planned Thermal and Short-Wave InfraRed (TIR and SWIR) space missions IASI (Infrared Atmospheric Sounding Interferometer), IASI-NG (IASI New Generation), MicroCarb (Carbon Dioxide Monitoring Mission), Merlin (MEthane Remote sensing LIdar missioN). It is actually a compilation of three databases: the “line parameters database”, the “cross-section sub-database” and the “microphysical and optical properties of atmospheric aerosols sub-database”. The new edition concerns only the line parameters dataset, with significant updates and additions implemented using the best available spectroscopic data. The GEISA-2020 line parameters database involves 58 molecules (145 isotopic species) and contains 6,746,987 entries, in the spectral range from 10−6 to 35877 cm−1. In this version, 23 molecules have been updated (with 10 new isotopic species) and 6 new molecules have been added (HONO, COFCl, CH3F, CH3I, RuO4, H2C3H2 (isomer of C3H4)) corresponding to 15 isotopic species. The compilation can be accessed through the AERIS data and services center for the atmosphere website (https://geisa.aeris-data.fr/), with the development of a powerful graphical tool and convenient searching, filtering, and plotting of data using modern technologies (PostgreSQL database, REST API, VueJS, Plotly). Based on four examples (H2O, O3, O2 and SF6), this paper also shows how the LMD in house validation algorithm SPARTE (Spectroscopic Parameters And Radiative Transfer Evaluation) helps to evaluate, correct, reject or defer the input of new spectroscopic data into GEISA and this, thanks to iterations with researchers from different communities (spectroscopy, radiative transfer)., SCOPUS: ar.j, info:eu-repo/semantics/published

The goal of this study is to measure for the first time absolute line intensities for the ν6 band of methyl iodide (CH3I) centered at 892.918 cm–1. High-resolution Fourier transform spectra were recorded at various pressures for the whole 500–1450 cm–1 spectral range. Using these spectra, a large set of CH3I individual line intensities was measured for the ν6 band. These experimental intensities were least squares fitted to derive the expansion of the ν6 transition moment operator. The theoretical model used to describe the line positions and intensities accounts for the hyperfine structure in the 61 and ground states and for the vibration-rotation resonances that couple the 61 energy levels with those of the 32 and 21 vibrational states [Perrin et al. J. Mol. Spectrosc. 324 (2016) 28–35]. As the 2ν3 band is extremely weak, its associated transition moment operator was estimated from band strength available in the literature. A comprehensive list of line positions and intensities was generated for the ν6 and 2ν3 bands of CH3I at 11 µm, which should be useful for the possible detection of this species by the future IASI-NG satellite instrument (Infrared Atmospheric Sounding Interferometer New Generation), now under preparation (https://iasi-ng.cnes.fr/en/IASI-NG/index.htm)., SCOPUS: ar.j, info:eu-repo/semantics/published

In this study we report the high-resolution measurements of oxygen pressure- broadening and pressure-induced shift coefficients for rovibrational transitions in the ν6 band of methyl iodide (12CH3I), centered at 892.918 cm–1. The results were obtained by analyzing fourteen high-resolution room temperature laboratory absorption spectra with a mono-spectrum non-linear least squares fitting of Voigt profiles. The data were recorded with the Bruker IF125HR Fourier transform spectrometer located at the LISA facility in Créteil, using a White type cell with a path length of 564.9 cm and total pressures up to 295 hPa. The measured oxygen-broadening coefficients range from 0.0648 to 0.1207 cm–1atm–1 at 295 K. The measured shift coefficients were all negative and varied between −0.00044 and −0.04984 cm–1atm–1. The average accuracy on the measured O2-broadening coefficients and pressure shift coefficients was estimated to about 4% and 11%, respectively. The O2-broadening coefficients obtained in the present work are compared with values reported in the literature for the ν5 band of CH3I, showing a satisfactory agreement with an average difference of about 8%. The shift coefficients are compared with values reported in the literature for the ν6 band of CH3F-Ar system, exhibiting the same order of magnitude and trend. The J and K rotational dependences of the O2-broadening coefficients have been observed and the latter modeled using empirical polynomial expansions. On average, the empirical expression reproduces the measured O2-broadening coefficients to within 3%. Using the measured broadening coefficients of the CH3I-O2 and CH3I-N2 [Attafi et al. J Quant Spectrosc Radiat Transf 231 (2019) 1–8] systems, we produced CH3I-air broadening coefficients, ranging from 0.0783 to 0.1385 cm–1atm–1 at 295 K. The present results and the data already available should be valuable not only for predicting the CH3I infrared spectrum in the atmosphere, but also for verifying theoretical calcula, SCOPUS: ar.j, info:eu-repo/semantics/published

The updated 2009 edition of the spectroscopic database GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques; 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 35,877.031cm-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/IASI/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 Météorologie 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 softwa, SCOPUS: ar.j, info:eu-repo/semantics/published