High-resolution absorption cross-section of glyoxal in the UV–vis and IR spectral ranges
15 May 2005-Journal of Photochemistry and Photobiology A-chemistry (Elsevier)-Vol. 172, Iss: 1, pp 35-46
TL;DR: In this article, high-resolution absorption cross-sections of glyoxal have been recorded at 296 k in the ultraviolet and visible (UV-vis: 19000-40000 cm−1, 250-526 k) spectral ranges by means of a Fourier transform spectrometer (FTS).
Abstract: High-resolution absorption cross-sections of glyoxal have been recorded at 296 K in the ultraviolet and visible (UV–vis: 19000–40000 cm−1, 250–526 nm) and infrared (IR: 1200–8000 cm−1) spectral ranges by means of a Fourier transform spectrometer (FTS). The UV–vis spectra were measured at 1 atm of N2 bath gas. The spectral resolution of the FTS was selected to be 0.06 cm−1 for the richly structured A ˜ 1Au – X ˜ 1Ag and a ˜ 3Au – X ˜ 1Ag band systems, and 1 cm−1 for the diffuse B ˜ − X ˜ transition, which was sufficient to resolve most spectral structures. In addition, low and high-resolution IR spectra (1 and 0.009 cm−1 spectral resolution) of glyoxal/N2 mixtures were recorded around 2835 cm−1 at 0.2 mbar, 100 mbar, 300 mbar and 1 atm total pressure. UV–vis and IR spectra were recorded quasi-simultaneously by making sequential measurements of identical glyoxal mixtures in the cell, enabling the direct comparison of UV–vis and IR spectral parameters for the first time. The high-resolution spectra have been used to simulate deviations from Lambert–Beer's law, which occur at lower resolution when spectra are not fully resolved. Special attention has been paid to reduce the uncertainty of the UV–vis spectrum, allowing for an improved determination of the atmospheric photolysis of glyoxal. Finally, the new UV–vis spectrum has been used to redetermine our previous DOAS measurements of glyoxal yields from the reactions of OH radicals with benzene, toluene and p-xylene. The high-resolution spectral data can be obtained from http://iup.physik.uni-bremen.de/gruppen/molspec/index.html or email request to the authors.
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TL;DR: In this paper, a detailed simulation of glyoxal and methylglyoxal in the GEOS-Chem global 3-D chemical transport model including the best knowledge of source and sink processes was conducted.
Abstract: [1] We construct global budgets of atmospheric glyoxal and methylglyoxal with the goal of quantifying their potential for global secondary organic aerosol (SOA) formation via irreversible uptake by aqueous aerosols and clouds. We conduct a detailed simulation of glyoxal and methylglyoxal in the GEOS-Chem global 3-D chemical transport model including our best knowledge of source and sink processes. Our resulting best estimates of the global sources of glyoxal and methylglyoxal are 45 Tg a−1 and 140 Tg a−1, respectively. Oxidation of biogenic isoprene contributes globally 47% of glyoxal and 79% of methylglyoxal. The second most important precursors are acetylene (mostly anthropogenic) for glyoxal and acetone (mostly biogenic) for methylglyoxal. Both acetylene and acetone have long lifetimes and provide a source of dicarbonyls in the free troposphere. Atmospheric lifetimes of glyoxal and methylglyoxal in the model are 2.9 h and 1.6 h, respectively, mostly determined by photolysis. Simulated dicarbonyl concentrations in continental surface air at northern midlatitudes are in the range 10–100 ppt, consistent with in situ measurements. On a global scale, the highest concentrations are over biomass burning regions, in agreement with glyoxal column observations from the SCIAMACHY satellite instrument. SCIAMACHY and a few ship cruises also suggest a large marine source of dicarbonyls missing from our model. The global source of SOA from the irreversible uptake of dicarbonyls in GEOS-Chem is 11 Tg C a−1, including 2.6 Tg C a−1 from glyoxal and 8 Tg C a−1 from methylglyoxal; 90% of this source takes place in clouds. The magnitude of the global SOA source from dicarbonyls is comparable to that computed in GEOS-Chem from the standard mechanism involving reversible partitioning of semivolatile products from the oxidation of monoterpenes, sesquiterpenes, isoprene, and aromatics.
578 citations
01 Dec 2007
467 citations
Cites background from "High-resolution absorption cross-se..."
...We assume a constant quantum yield of 0.021 above 445 nm, resulting in an effective quantum yield of 0.035 averaged over the solar spectrum at sea level that matches the measured values of 0.029–0.035 for that quantity [Plum et al., 1983; Volkamer et al., 2005a; Tadić et al., 2006]....
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...…concentrations can exceed 1 ppb due to emissions of very short-lived anthropogenic precursors [Grosjean et al., 1996, 2002; Ho and Yu, 2002a, 2002b; Volkamer et al., 2005b; Liu et al., 2006; Possanzini et al., 2007], but such local enhancements would not be resolved by our global model....
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...Primary anthropogenic emissions of glyoxal and methylglyoxal are small [Environmental Protection Agency, 2004; Volkamer et al., 2005b] and are not considered here....
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TL;DR: In this paper, the authors compared direct measurements of gas-phase glyoxal in Mexico City with experimentally constrained model predictions and found that the observed glyoxion concentrations were significantly below those predicted; an additional glyoxification sink must be operative.
Abstract: [1] The sources of secondary organic aerosol (SOA) are highly uncertain Direct measurements of gas-phase glyoxal in Mexico City are compared to experimentally constrained model predictions Observed glyoxal concentrations are found significantly below those predicted Additional glyoxal sources are likely and would increase these differences; an additional glyoxal sink must be operative The model-measurement differences are fully resolved by a sink parameterized from aerosol parameters as either (1) irreversible uptake to aerosol surface area (uptake coefficient γ ≈ 00037); reversible partitioning to (2) aerosol liquid water (effective Henry's law coefficient Heff ≈ 4 × 109 M atm−1), or (3) the oxygenated organic aerosol phase (activity coefficient ζ ≈ 6 × 10−9); (4) a combination of the above The missing sink has the potential to determine 70–95% of the atmospheric lifetime of glyoxal The glyoxal imbalance corresponds to several μg m−3 of equivalent SOA mass, and can explain at least 15% of the SOA formation in Mexico City
427 citations
TL;DR: In this article, the lightest non-methane hydrocarbon (NMHC) is found to form secondary organic aerosol (SOA), and the number of carbon atoms, n, for a NMHC to act as SOA precursor is lowered to n=2.
Abstract: . The lightest Non Methane HydroCarbon (NMHC), i.e., acetylene (C2H2) is found to form secondary organic aerosol (SOA). Contrary to current belief, the number of carbon atoms, n, for a NMHC to act as SOA precursor is lowered to n=2 here. The OH-radical initiated oxidation of C2H2 forms glyoxal (CHOCHO) as the highest yield product, and >99% of the SOA from C2H2 is attributed to CHOCHO. SOA formation from C2H2 and CHOCHO was studied in a photochemical and a dark simulation chamber. Further, the experimental conditions were varied with respect to the chemical composition of the seed aerosols, mild acidification with sulphuric acid (SA, 3
336 citations
Pierre-and-Marie-Curie University1, University of Reims Champagne-Ardenne2, Centre national de la recherche scientifique3, College of William & Mary4, Paris Diderot University5, University of Burgundy6, California Institute of Technology7, Belgian Institute for Space Aeronomy8, Université catholique de Louvain9, University of Denver10, Université libre de Bruxelles11, University College London12, University of New Brunswick13, University of Calgary14, University of Cologne15, Karlsruhe Institute of Technology16, Wright State University17, University of Lethbridge18, Langley Research Center19, University of Leicester20
TL;DR: The GEISA database as mentioned in this paper 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.
Abstract: 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/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 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.
332 citations
References
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01 Jan 1999
TL;DR: In this article, the photo-dissociation rate coefficients (J values) are used to understand the behavior of global stratospheric and tropospheric ozone, the atmospheric lifetimes of gases such as carbon monoxide, methane, and non-methane hydrocarbons, and the formation of oxidants at urban and regional scales.
Abstract: Solar radiation at visible and ultraviolet wavelengths drives the chemistry of the atmosphere, by photo-dissociating relatively stable molecules into highly reactive radical fragments. Knowledge of photo-dissociation rate coefficients (J values) is crucial to understanding the behavior of global stratospheric and tropospheric ozone, the atmospheric lifetimes of gases such as carbon monoxide, methane, and non-methane hydrocarbons, and the formation of oxidants at urban and regional scales. J values depend on molecular parameters (absorption cross sections and photo-dissociation quantum yields) that are specific to the photo-reaction of interest, and on the availability of solar radiation at any specific location in the atmosphere. Advances in computer modeling of atmospheric radiative transfer now allow rapid calculation of J values for use in photo-chemistry models, and routinely include the effects of molecular absorbers and scatterers, clouds, aerosols, and surface reflections, for any location and time of the year. However, actual atmospheric conditions needed as input to the calculation are often not available. Direct measurements of J values, while in principle preferable, are technically difficult and limited in their temporal/spatial coverage, but generally support the theoretical calculations at least under optimal conditions (e. g., cloud free skies).
537 citations
Book•
14 Feb 2002
TL;DR: In this article, the importance of aromatic hydrocarbons in the chemistry of ozone generation in the urban atmosphere has been discussed, and some common products of the atmospheric oxidation of the aromatic compounds of polycyclic aromatic hydrocbons are discussed.
Abstract: Acknowledgments 1: Importance of aromatic hydrocarbons in the chemistry of ozone generation in the urban atmosphere 2: Reactions of aromatic compounds with OH radicals 3: Reactions of monocyclic and polycyclic aromatic compounds with NO[3 radicals 4: Reactions of ozone with aromatic compounds 5: Reactions of O((3)P) atoms with aromatic compounds 6: Reactions of non-aromatic products of aromatic compound oxidation 7: Primary photochemical processes of the aromatic hydrocarbons and some of their common oxidation products 8: Aerosol generation in atmospheric oxidation of aromatic hydrocarbons 9: Atmospheric chemistry of polycyclic aromatic hydrocarbons sorbed on particles 10: Application of findings to modeling the atmostpheric chemistry of aromatic hydrocarbons 11: Important areas for further laboratory studies 12: Summary References Appendix I: Nomenclature and molecular structure of aromatic hydrocarbons Appendix II: Nomenclature and molecular structure of some common products of the atmospheric oxidation of the aromatic hydrocarbons Author Index Subject Index
438 citations
"High-resolution absorption cross-se..." refers background in this paper
...In particular, glyoxal is an important ring-cleavage product in the OH-radical initiated oxidation of aromatic hydrocarbons [1–4], and is also formed in the reaction of O3 and OH-radicals with some alkenes [5–8] and...
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...[1] J....
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TL;DR: In this paper, a new approach is presented to study the ring-cleavage process of benzene, toluene, and p-xylene (BTX) in a series of experiments at the EUPHORE outdoor simulation chamber.
Abstract: A new approach is presented to study the ring-cleavage process of benzene, toluene, and p-xylene (BTX). DOAS (differential optical absorption spectroscopy) was used for the simultaneous measurement of the respective ring-retaining products as well as glyoxal (a ring-cleavage product) in a series of experiments at the EUPHORE outdoor simulation chamber, Valencia/Spain. The good time resolution of the DOAS measurements (1-2 min) allowed the primary formation of glyoxal to be separated from any further contributions through additional pathways via reactions of stable intermediate compounds (secondary glyoxal formation). The ring-retaining products and glyoxal were identified as primary products. The primary glyoxal yield was found to be essentially identical to the overall yield of glyoxal formed over the time scale of the experiments. The negligible contribution from secondary glyoxal formation pathways was quantitatively understood for the experimental conditions of this study and was found to be representative for the troposphere. The yield of glyoxal was determined to be 35% ( 10% for benzene and about 5% higher for toluene and p-xylene. For benzene, the yield of hexadienedial was estimated to be e 8%. It is concluded that ringcleavage pathways involving the bicycloalkyl radical are major pathways in the oxidation of monocyclic aromatic hydrocarbons, i.e., BTX. The branching ratio for the bicycloalkyl radical intermediate, proposed to form from the reaction of the aromatic-OH adduct with atmospheric oxygen, could be directly identified with the primary glyoxal yield for the benzene system and as a lower limit in the case of toluene and p-xylene. Implications for the chemical behavior of aromatic hydrocarbons in the atmosphere are discussed.
269 citations
TL;DR: Aromatic carbonyls, unsaturatedAliphatic aldehydes, and aliphatic dicarbonyls represented larger fractions of the total carbonyl emissions for 7-8 HD vehicles than for LD vehicles, and formaldehyde and acetaldehyde emission factors measured in this study are generally lower than those measured in earlier work.
Abstract: Vehicle emissions are a major source of carbonyls, which play an important role in atmospheric chemistry and urban air quality. Yet, little data are available for speciated carbonyls emitted by veh...
201 citations