The HITRAN2020 molecular spectroscopic database Gordon, I.E.; Rothman, L.S.; Hargreaves, R.J. ...
Journal of Quantitative Spectroscopy & Radiative Transfer/Journal of quantitative spectroscopy & radiative transfer,
01/2022, Volume:
277
Journal Article
Peer reviewed
Open access
•The HITRAN2020 molecular spectroscopic database and its validations are presented.•Extended line-by-line coverage to 55 molecules, with new isotopologues included.•Increased spectral and dynamic ...ranges for multiple molecules.•Quality and amount of spectral parameters (including sophisticated line shapes) is increased.•Updates to cross sections, CIA, software tools & auxiliary data also described.
The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years).
All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules.
The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition.
Improving the understanding of processes related to atmospheric particle sources is essential to better assess future climate. Especially, how biogenic volatile organic compounds (BVOCs) are involved ...in new particle formation (NPF) is still unclear, highlighting the need for field studies in sites that have not yet been explored. Weakly anthropised, mostly composed of maritime pines (known as strong monoterpene emitters), vast and under the influence of sea spray inputs, the Landes forest (located in the southwestern part of France) is a suitable ecosystem to explore these questions. The aim of the present work was to investigate for the first time NPF in the Landes forest, and to identify the conditions for NPF. During a field campaign conducted in July 2015, clear NPF was observed during nighttime, at a high frequency rate (37.5%), whereas only two daytime episodes were observed. Growth rates during NPF events were in the range 9.0–15.7nmh−1, and nucleation rates (J10) in the range 0.8–8 particles cm3s−1, typically in the range of reported values from rural sites. Nocturnal NPF started at sunset, lagging the reductions of temperature and ozone concentration as well as the increase of relative humidity, atmospheric stability and monoterpene concentration. We established that NPF occurred during more stratified atmosphere episodes, reflecting that NPF is more influenced by local processes at the Landes forest site (Bilos). Concentration of the sum of monoterpenes, here mainly α- and β-pinene, was observed to be maximal during NPF episodes. On the contrary, ozone concentration was lower, which may indicate a larger consumption during nights where NPF episodes occur. Results strongly suggest the contribution of BVOC oxidation to nocturnal NPF, in both nucleation and the growth stages.
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•Nocturnal new particle formation (NPF) was emphasized.•Monoterpene concentrations, mainly α- and β-pinene, were maximal during NPF.•Results suggest that BVOC oxidation is involved in nocturnal NPF.
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•GEISA-2020 database release: 6,746,987 entries in the line parameters database.•23 molecules updated and 6 new molecules added (HONO, COFCl, CH3F, CH3I, RuO4, H2C3H2 (isomer of ...C3H4).•Evaluation of the spectroscopic parameters through radiative transfer simulations compared to atmospheric spectra (SPARTE chain).
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).
The HITRAN2016 molecular spectroscopic database Gordon, I.E.; Rothman, L.S.; Hill, C. ...
Journal of Quantitative Spectroscopy & Radiative Transfer/Journal of quantitative spectroscopy & radiative transfer,
12/2017, Volume:
203
Journal Article
Peer reviewed
Open access
•HITRAN2016 molecular spectroscopic database is described.•Dynamic web interface at www.hitran.org is introduced.•HITRAN Application Programming Interface is introduced.•Substantial extent of the ...amount and quality of the data highlighted.•Many new spectroscopic parameters are now available in HITRAN.
This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided.
•Fourier transform N2-broadened spectra of phosgene in the mid-infrared.•Integrated band intensities and absorption cross sections.•Temperature dependence of the phosgene integrated band intensities.
...Integrated band intensities and absorption cross-sections of phosgene (Cl2CO) have been measured at different temperatures (199, 250 and 300 K) to support remote sensing applications, particularly for an accurate quantification of Cl2CO in the Earth's atmosphere. To our knowledge and prior to this study, no previous work has examined the temperature dependence of the phosgene integrated band intensities. Series of N2-broadened spectra of phosgene were recorded from 525 to 2400 cm−1, at a resolution of 0.1 cm−1, using a Bruker IFS125HR Fourier transform spectrometer located at the LISA facility in Créteil, France. The pressure of each phosgene vapor sample was measured using high precision capacitance manometers and a minimum of six sample pressures were recorded for each temperature. The samples were introduced into an especially designed, short optical path length (5.10 ± 0.01 cm), coolable cell, that was mounted inside the spectrometer. From these spectra, integrated band intensities for six spectral regions corresponding to the ν2/ν4, ν5, ν2 + ν6, ν2 + ν5, 2ν5 and ν1 bands were obtained from room temperature down to 199 K. We discussed and quantified error sources and, on average, the estimate accuracy for the measured integrated band intensities is equal to 4%. Measurements at room temperature were compared with previously reported values. Our results at 300 K, show an excellent agreement (better than 4%) with the Hopper et al. J Chem Phys (1968) values, agree reasonably well with those from the PNNL database (better than 9% for the stronger ν1 and ν5 bands of atmospheric interest), but depart strongly from the measurements of Lovell and Jones J Mol Spectrosc (1960) for which there are differences between 20 and 43%. In addition, our results at low temperatures show a non-negligible temperature dependence (7.5 to ∼31%, depending on the bands, between 300 and 199 K), probably due to the presence of hot bands and possible overlapping neighboring bands such as overtones and combination/difference bands. To better understand these temperature variations a detailed high resolution investigation of pure Cl2CO spectra over a wide range of temperature would be necessary.
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Formaldehyde plays a key role in atmospheric photochemistry and is particularly important for the production of HOx species. For measuring atmospheric formaldehyde concentrations, both midinfrared ...and ultraviolet (UV) absorption techniques are used by ground‐, air‐ or satellite‐based instruments. In order to obtain accurate formaldehyde concentrations, the knowledge of the absorption cross sections is of utmost importance. In this study, we report the first laboratory intercomparison of the absorption coefficients of formaldehyde using simultaneous measurements in both spectral regions. The intercomparison shows good agreement between selected accurate UV spectra published previously and different infrared data. On the contrary, a rather large disagreement (about 20%) is observed when using other UV data sets, such as those recommended currently by the HITRAN database.
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