NH3 and PH3 line parameters: the 2000 HITRAN update and new results

The infrared spectrum of CH3D from 3250 to 3700 cm =1 was studied for the rst time to assign transitions involving the ν2+ν3, ν2+ν5, ν2+ν6, ν3+2ν6 and 3ν6 vibrational states. Line positions and intensities were measured at 0.011 cm =1 resolution using Fourier transform spectra recorded at Kitt Peak with isotopically enriched samples.Some 2852 line positions (involving over 900 upper state levels) and 874 line intensities were reproduced with RMS values of 0.0009 cm =1 and 4.6%, respectively. The strongest bands were found to be ν2 + ν3 at 3499.7 cm =1 and ν2 + ν6 at 3342.5 cm =1 with integrated strengths, respectively, of 8.17 Ö 10 =20 and 2.44 Ö 10 =20 (cm =1 /molecule · cm =2 ) at 296 K (for 100% CH3D). The eective Hamiltonian was expressed in terms of irreducible tensor operators and adapted to symmetric top molecules. Its present conguration in the MIRS package permitted simultaneous consideration of the four lowest polyads of CH3D: the Ground State (G.S.), the Triad from 6.3 to 9.5 mm, the Nonad from 3.1 to 4.8 mm and now the Enneadecad (19 bands) from 2.2 to 3.1 mm. The CH3D line parameters for this interval were calculated to create a new database for the 3 mm region.

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“…6. Signicantly, the present study reveals that features of CH 3 D overlap those of the NH 3 fundamentals near 3330 cm =1 [23] and also …”

Section: =25supporting

confidence: 59%

Preliminary analysis of CH3D from 3250 to 3700cm−1

Nikitin

Champion

Brown

2006

Journal of Molecular Spectroscopy

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“…Opacity due to tropospheric aerosols is absent from our model as they are not expected to have an effect at these long wavelengths. Foreign broadening of the line intensities (obtained from Kleiner et al 2003) by H 2 and He was calculated using the empirical model of Brown & Peterson (1994), which reproduces experimentally-measured line widths to an 11% accuracy. Furthermore, Table III of Brown & Peterson (1994) suggests an experimental precision of 5-7% on the intensities and 3-6% on line widths for those rotational lines observed by SPIRE.…”

Section: Ammonia Nhmentioning

confidence: 93%

“…The PH 3 lines were broadened by both H 2 and He using γ H 2 = 0.1078−0.0014J cm −1 atm −1 and γ He = 0.0618−0.0012J cm −1 atm −1 (Levy et al 1993), and a temperature dependence of T n where n = 0.702−0.01J (J is the rotational quantum number). For NH 3 we use line data from Kleiner et al (2003), hydrogen-and helium-broadened using the empirical model of Brown & Peterson (1994). A Rosenkrantz Ben-Reuven lineshape was assumed for ammonia (using line coupling from Eq.…”

Section: Saturn Continuum Modelling: Temperatures Ph 3 and Nhmentioning

confidence: 99%

Sub-millimetre spectroscopy of Saturn’s trace gases fromHerschel/SPIRE

Fletcher

Swinyard

Salji

et al. 2012

A&A

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Aims. We provide an extensive new sub-millimetre survey of the trace gas composition of Saturn's atmosphere using the broad spectral range (15-51 cm −1 ) and high spectral resolution (0.048 cm −1 ) offered by Fourier transform spectroscopy by the Herschel/SPIRE instrument (Spectral and Photometric Imaging REceiver). Observations were acquired in June 2010, shortly after equinox, with negligible contribution from Saturn's ring emission. Methods. Tropospheric temperatures and the vertical distributions of phosphine and ammonia are derived using an optimal estimation retrieval algorithm to reproduce the sub-millimetre data. The abundance of methane, water and upper limits on a range of different species are estimated using a line-by-line forward model. Results. Saturn's disc-averaged temperature profile is found to be quasi-isothermal between 60 and 300 mbar, with uncertainties of 7 K due to the absolute calibration of SPIRE. Modelling of PH 3 rotational lines confirms the vertical profile derived in previous studies and shows that negligible PH 3 is present above the 10-to 20-mbar level. The upper tropospheric abundance of NH 3 appears to follow a vapour pressure distribution throughout the region of sensitivity in the SPIRE data, but the degree of saturation is highly uncertain. The tropospheric CH 4 abundance and Saturn's bulk C/H ratio are consistent with Cassini studies. We improve the upper limits on several species (H 2 S, HCN, HCP and HI); provide the first observational constraints on others (SO 2 , CS, methanol, formaldehyde, CH 3 Cl); and confirm previous upper limits on HF, HCl and HBr. Stratospheric emission from H 2 O is suggested at 36.6 and 38.8 cm −1 with a 1σ significance level, and these lines are used to derive mole fractions and column abundances consistent with ISO and SWAS estimations a decade earlier.

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“…The spectroscopic line in HI-TRAN 2004 (Rothman et al, 2005) originated from the HI-TRAN 2000 compilation (Rothman et al, 2003). Those parameters were described in the paper by Kleiner et al (2003). Intensities for 14 NH 3 near the 10 µm (the only isotopologue of significance for the present work) were derived from laboratory measurements at the US National Solar Observatory.…”

Section: Retrieval Error Analysismentioning

confidence: 99%

TES ammonia retrieval strategy and global observations of the spatial and seasonal variability of ammonia

et al. 2011

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Abstract. Presently only limited sets of tropospheric ammonia (NH 3 ) measurements in the Earth's atmosphere have been reported from satellite and surface station measurements, despite the well-documented negative impact of NH 3 on the environment and human health. Presented here is a detailed description of the satellite retrieval strategy and analysis for the Tropospheric Emission Spectrometer (TES) using simulations and measurements. These results show that: (i) the level of detectability for a representative boundary layer TES NH 3 mixing ratio value is ∼0.4 ppbv, which typically corresponds to a profile that contains a maximum level value of ∼1 ppbv; (ii) TES NH 3 retrievals generally provide at most one degree of freedom for signal (DOFS), with peak sensitivity between 700 and 900 mbar; (iii) TES NH 3 retrievals show significant spatial and seasonal variability of NH 3 globally; (iv) initial comparisons of TES observations with GEOS-CHEM estimates show TES values being higher overall. Important differences and similarities between modeled and observed seasonal and spatial trends are noted, with discrepancies indicating areas where the timing and magnitude of modeled NH 3 emissions from agricultural sources, and to lesser extent biomass burning sources, need further study.

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NH3 and PH3 line parameters: the 2000 HITRAN update and new results

Cited by 66 publications

References 88 publications

Preliminary analysis of CH3D from 3250 to 3700cm−1

Preliminary analysis of CH3D from 3250 to 3700cm−1

Sub-millimetre spectroscopy of Saturn’s trace gases fromHerschel/SPIRE

TES ammonia retrieval strategy and global observations of the spatial and seasonal variability of ammonia

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