The ammonia spectrum is revisited in the important 1.6 µm atmospheric transparency window between 5650 and 6350 cm
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on the basis of recently recorded high-resolution Fourier transform ...spectra. These spectra offer an improved frequency sampling and better traceability of the measurement conditions compared to previously studied Kitt Peak spectra (Cacciani et al. J. Quant Spectrosc Radiat Transf 2021; 258:107334. https://doi.org/10.1016/j.jqsrt.2020.107334). Overall, 4812
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NH
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3
lines were measured in the 5650-6350 cm
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region corresponding to 4866 transitions including 2066 new ones compared with our previous study, included in the HITRAN2020 database. The energy of 1023 upper state levels (including 107 new ones) was derived from 2608 assigned transitions. Independently, ammonia spectra recorded in a supersonic jet expansion using a tunable extended cavity diode laser allow us to check the absolute transition energies in the 5980-6080 cm
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range. Accurate jet spectra calibration was achieved using CH
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reference line positions known with kHz accuracy. The position agreement with the FTS data is within the
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×
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cm
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uncertainty of the positions measured in the jet expansion. A recommended line list of 5620 transitions is provided for
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NH
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in the considered 5650-6350 cm
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region.
We report the measurement of broadening coefficients of pure rotational lines of methane at different pressure and temperature conditions. A total of 27 far-infrared spectra were recorded at the ...AILES beamline of the SOLEIL synchrotron at room-temperature, 200K and 120K, in a range of 10 to 800mbar. Self and N2 broadening coefficients and temperature dependence exponents of methane pure rotational lines have been measured in the 73–136cm−1 spectral range using multi-spectrum non-linear least squares fitting of Voigt profiles. These coefficients were used to model spectra of Titan that were compared to a selection of equatorial Cassini/CIRS spectra, showing a good agreement for a stratospheric methane mole fraction of (1.17 ± 0.08)%.
•Far-infrared high-resolution spectroscopy of methane rotational lines.•Pressure broadening of pure rotational lines at low temperature.•Coefficients measured were used to model spectra of Titan that were compared to a selection of equatorial Cassini/CIRS spectra.
The HITRAN 2004 molecular spectroscopic database Rothman, L.S.; Jacquemart, D.; Barbe, A. ...
Journal of quantitative spectroscopy & radiative transfer,
12/2005, Volume:
96, Issue:
2
Journal Article
Peer reviewed
Open access
This paper describes the status of the 2004 edition of the
HITRAN molecular spectroscopic database. 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 unresolvable; individual line parameters and absorption cross-sections for bands in the ultra-violet; 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 39 molecules including many of their isotopologues.
The format of the section of the database on individual line parameters of
HITRAN has undergone the most extensive enhancement in almost two decades. It now lists the Einstein
A
-coefficients, statistical weights of the upper and lower levels of the transitions, a better system for the representation of quantum identifications, and enhanced referencing and uncertainty codes. In addition, there is a provision for making corrections to the broadening of line transitions due to line mixing.
Two magmatic suites were emplaced during the post-collisional evolution of the Sveconorwegian orogeny: an Anorthosite–Mangerite–Charnockite suite (AMC suite), and an hornblende- and biotite-bearing ...granitoids suite (HBG suite). The AMC suite is exclusively located in the westernmost and warmest part of the orogen, in granulite facies gneisses, whereas the HBG suite intruded in the rest of the orogen, but not in the granulite domain. New U–Pb zircon geochronological data confirm previous age determinations: 970–932
Ma (HBG suite) and 933–916
Ma (AMC suite).
The mafic facies of the two post-collisional magmatic suites have similar geochemical compositions but the HBG differentiation trend displays higher CaO, Sr, U and Th as well as lower K
2O and FeO
t/MgO than the AMC differentiation trend. The HBG suite is hydrous and has a broadly higher fO
2 whereas the AMC suite is anhydrous.
The inferred parent magmas of both suites have overlapping initial Sr, Nd and Pb isotopic compositions. With increasing differentiation, the two trends point towards two different crustal contaminants. Together with the recent recognition of a major crustal shear zone located just east of the AMC suite, this difference suggests that the suites were emplaced in two different lithotectonic units.
Using published experimental constraints and geochemical modeling, we suggest that the mafic facies of both suites were produced by partial melting of lower crustal sources which were previously underplated, probably during the evolution of a long-lasting convergent margin. Later, these lower crustal sources were modified by the regional granulite facies metamorphism (1.035 to 0.97
Ga) prevailing in the westernmost part of the orogen, thus producing an anhydrous lower crustal source for the AMC suite.
Accordingly, we conclude that the Sveconorwegian massif-type anorthosites result from partial melting of the continental arc root. This process, if accepted for other AMCG (Anorthosite–Mangerite–Charnockite–Granite) complexes, was possible in the Proterozoic because of a sufficiently high temperature, but not in the Archean because in subduction zones the main transfer to the crust was then felsic (tonalites, granodiorites) and not basaltic. We thus further suggest that the onset of massif-type anorthosites at the beginning of the Proterozoic may mark the time when plate tectonics began to operate in a similar way as today.
► We compare the geochemistry and petrology of the two post-collisional sveconorwegian (0.97 – 0.92
Ga) magmatic suites. ► New geochronological data (U-Pb zircon) confirm previous age determinations. ► The two post-collisional sveconorwegian magmatic suites were emplaced in two different lithotectonic units. ► The parent magmas of bothmagmatic suitesresult from partial melting of a continental arc root. ► The regional granulite metamorphism produced an anhydrous crustal source for the Anorthosite-Mangerite-Charnockite suite.
•Determination of the energy difference (ΔECis-Trans) between the Cis- and Trans-HONO conformers of nitrous acid.•Relative line intensities for the B-type transitions of pure rotational bands of ...Trans-HONO and Cis-HONO measured.•Far infrared FTS spectra on SOLEIL.•Line list for HONO in the far infrared region.
The first goal of this work is to improve the determination of the energy difference (ΔECis-Trans) between the ground vibrational state of the Cis- and Trans-HONO conformers of nitrous acid. For this, high resolution spectra were recorded in the 50–200 cm−1 spectral region at three different temperatures, 240, 270 and 296 K. The relative line intensities for the B-type transitions of pure rotational bands of Trans-HONO and Cis-HONO achieved from our measurements were combined in least squares fit computations to those measured previously by Sironneau et al. Sironneau V, Flaud JM, Orphal J, Kleiner I, Chelin P. Absolute line intensities of HONO and DONO in the far-infrared and re-determination of the Energy Difference between the trans- and cis-species of nitrous acid. J Mol Spectrosc 2010;259:100–104. In this way, we can significantly improve the accuracy on the HONO conformer energy difference, with a value for ΔECis-Trans = 95.8 ± 9.2 cm−1 compared to SIRΔECis-Trans = 99 ± 25 cm−1 in the previous study of Sironneau et al. The second goal is to generate a line list with “absolute” line intensities for the pure rotational bands in the far infrared region of Trans-HONO and Cis-HONO, with both A- and B-type transitions. This new line list proved to be more robust for an improved detection of HONO in astrophysical objects Coutens A, Ligterink NFW, Loison JC, Wakelam V, Calcutt H, Drozdovskaya MN, Jørgensen JK, Müller HSP, Van Dishoeck EF, Wampfler SF. The ALMA-PILS survey: First detection of nitrous acid (HONO) in the interstellar medium. Astronomy & Astrophysics 2019;623:L13.
Comparison of the ALMA observations of the HONO transitions towards the protostar IRAS16293 B (black) with the model obtained with the JPL line list for Tex = 300 K and N = 1.4 1015 cm−2 blue dashed line) and the one obtained with our new line list for similar parameters (red solid line). Display omitted
The positions and intensities of 1936 lines observed in the range 7400-
of two absorption spectra of ammonia recorded at high resolution using Fourier transform spectroscopy are reported. The ...accuracy of these line positions is estimated to range from 0.001 to
from the lower to the upper limits of the spectral range considered, while the accuracy of the line intensities is estimated to be around 10% or better. Also reported are less-accurately measured positions and intensities of 1985 lines retrieved from these two spectra or from only one of them. These results are compared with the data measured recently in a spectrum recorded in 1980 at the Kitt Peak National Solar Observatory Barton et al., J. Mol. Spectrosc. 325, 7 (2016) and provided in HITRAN 2016, as well as line positions and intensities measured in this work in the same Kitt Peak spectrum.
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