The role of highly oxygenated organic molecules in the Boreal aerosol-cloud-climate system

Nature Communications, Год журнала: 2019, Номер 10(1)

Опубликована: Сен. 25, 2019

Abstract Over Boreal regions, monoterpenes emitted from the forest are main precursors for secondary organic aerosol (SOA) formation and primary driver of growth new particles to climatically important cloud condensation nuclei (CCN). Autoxidation leads rapid Highly Oxygenated Molecules (HOM). We have developed first model with near-explicit representation atmospheric particle (NPF) HOM formation. The can reproduce observed NPF, gas-phase composition SOA over forest. During spring, increases CCN concentration by ~10 % causes a direct radiative forcing −0.10 W/m 2 . In contrast, NPF reduces number at updraft velocities < 0.2 m/s, +0.15 Hence, while contributes climate cooling, result in warming

Язык: Английский

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Overlooked Formation of H₂O₂ during the Hydroxyl Radical-Scavenging Process When Using Alcohols as Scavengers

Environmental Science & Technology, Год журнала: 2022, Номер 56(6), С. 3386 - 3396

Опубликована: Март 1, 2022

Hydroxyl radical (•OH) is an active species widely reported in studies across many scientific fields, and hence, its reliable analysis vitally important. Currently, alcohols are commonly used as scavengers for •OH determination. However, the impacts of on reliability detection remain unknown. In this study, we found that adding different types amounts water samples treated with ultraviolet irradiation undesirably produced substantial hydrogen peroxide (H2O2), which a known precursor. This means conventional determination method using likely unreliable or even misleading. Through careful investigation, revealed overlooked reaction pathway during H2O2 transformations. Varying oxygen concentrations, pHs, alcohol dosages, altered formation, can affect accuracy. Among alcohols, n-butanol best scavenger because it quenches rapidly but re-forms little H2O2.

Язык: Английский

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Modeling the formation and growth of atmospheric molecular clusters: A review

Journal of Aerosol Science, Год журнала: 2020, Номер 149, С. 105621 - 105621

Опубликована: Июль 3, 2020

Язык: Английский

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Multi-generation OH oxidation as a source for highly oxygenated organic molecules from aromatics

Atmospheric chemistry and physics, Год журнала: 2020, Номер 20(1), С. 515 - 537

Опубликована: Янв. 15, 2020

Abstract. Recent studies have recognised highly oxygenated organic molecules (HOMs) in the atmosphere as important formation of secondary aerosol (SOA). A large number focused on HOM from oxidation biogenically emitted monoterpenes. However, anthropogenic vapours has so far received much less attention. Previous identified importance aromatic volatile compounds (VOCs) for SOA formation. In this study, we investigated several compounds, benzene (C6H6), toluene (C7H8), and naphthalene (C10H8), their potential to form HOMs upon reaction with hydroxyl radicals (OH). We performed flow tube experiments all three VOCs detail Jülich Plant Atmosphere Chamber (JPAC). JPAC, also response NOx seed aerosol. Using a nitrate-based chemical ionisation mass spectrometer (CI-APi-TOF), observed reactor first OH attack. naphthalene, which were injected at lower concentrations, multi-generation seemed impact composition. tested more system allowed studying longer residence times. The results showed that apparent molar yield under our experimental conditions varied 4.1 % 14.0 %, strong dependence concentration, indicating majority formed through multiple OH-oxidation steps. composition spectrum supported hypothesis. By injecting only phenol into chamber, found cannot be solely responsible experiments. When was added changed many nitrogen-containing products CI-APi-TOF. Upon injection, loss rate higher than predicted by irreversible condensation, suggesting some undetected intermediates condensed onto aerosol, is line hypothesis oxidation. Based results, conclude systems strongly depend VOC concentration are needed fully understand effect and, consequently, SOA. suggest chamber may explain part variability yields reported literature advise monitoring future studies.

Язык: Английский

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Fast Peroxy Radical Isomerization and OH Recycling in the Reaction of OH Radicals with Dimethyl Sulfide

The Journal of Physical Chemistry Letters, Год журнала: 2019, Номер 10(21), С. 6478 - 6483

Опубликована: Окт. 7, 2019

Dimethyl sulfide (DMS), produced by marine organisms, represents the most abundant, biogenic sulfur emission into Earth's atmosphere. The gas-phase degradation of DMS is mainly initiated reaction with OH radical forming first CH3SCH2O2 radicals from dominant H-abstraction channel. It experimentally shown that these peroxy undergo a two-step isomerization process finally product consistent formula HOOCH2SCHO. accompanied recycling. rate-limiting step, → CH2SCH2OOH, followed O2 addition, proceeds k = (0.23 ± 0.12) s-1 at 295 2 K. Competing bimolecular reactions NO, HO2, or RO2 are less important for trace-gas conditions over oceans. Results atmospheric chemistry simulations demonstrate predominance (≥95%) isomerization. rapid isomerization, not yet considered in models, substantially changes understanding DMS's processes

Язык: Английский

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Evaluating the sensitivity of radical chemistry and ozone formation to ambient VOCs and NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; in Beijing

Atmospheric chemistry and physics, Год журнала: 2021, Номер 21(3), С. 2125 - 2147

Опубликована: Фев. 12, 2021

Abstract. Measurements of OH, HO2, complex RO2 (alkene- and aromatic-related RO2) total radicals taken during the integrated Study AIR Pollution PROcesses in Beijing (AIRPRO) campaign central summer 2017, alongside observations OH reactivity, are presented. The concentrations were elevated, with reaching up to 2.8×107moleculecm-3, HO2 peaking at 1×109moleculecm-3 concentration 5.5×109moleculecm-3. reactivity (k(OH)) peaked 89 s−1 night, a minimum afternoon ≈22s-1 on average. An experimental budget analysis, which rates production destruction compared, highlighted that although sources sinks balanced under high NO concentrations, exceeded known (by 15 ppbv h−1) very low conditions (<0.5 ppbv) experienced afternoons, demonstrating missing source consistent previous studies volatile organic compound (VOC) emissions loadings. Under highest mixing ratios (104 ppbv), rate by ≈50ppbvh-1, whilst same rate, indicating net propagation may be substantially slower than assumed. If just 10 % propagate upon reaction NO, budgets could closed but this lower revealed sink was similar magnitude source. A detailed box model incorporated latest Master Chemical Mechanism (MCM3.3.1) reproduced observed well over-predicted (<1 under-predicted (both fraction other types we classify as simple most significantly concentrations. also k(OH) consistently ≈10s-1 across all NOx levels, highlighting good agreement for fortuitous due cancellation terms its budget. Including heterogeneous loss aerosol surfaces did reduce modelled line only <0.3 ppbv. inclusion Cl atoms, formed from photolysis nitryl chloride, enhanced several mornings when atom calculated exceed 1×104atomscm-3 reconcile measured these times. However, mornings, lower, large under-predictions remained. Furthermore, chemistry not enhance beyond first few hours after sunrise so unable resolve under-prediction times day. Model scenarios, VOC included an additional converted RO2, sensitive choice product. level simple) improved if larger species able undergo followed isomerisation reactions reforming species, before eventually generating HO2. In work α-pinene-derived used example. simulation, underestimated uncertainty, regards present they form (HO2 directly or another species), leads over order less O3 predicted peroxy This demonstrates indeed needs understood accurately simulate ozone environments such Beijing, where multifunctional VOCs likely present.

Язык: Английский

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Organic Peroxides in Aerosol: Key Reactive Intermediates for Multiphase Processes in the Atmosphere

Chemical Reviews, Год журнала: 2023, Номер 123(4), С. 1635 - 1679

Опубликована: Янв. 11, 2023

Organic peroxides (POs) are organic molecules with one or more peroxide (−O–O−) functional groups. POs commonly regarded as chemically labile termination products from gas-phase radical chemistry and therefore serve temporary reservoirs for oxidative radicals (HOx ROx) in the atmosphere. Owing to their ubiquity, active gas-particle partitioning behavior, reactivity, key reactive intermediates atmospheric multiphase processes determining life cycle (formation, growth, aging), climate, health impacts of aerosol. However, there remain substantial gaps origin, molecular diversity, fate due complex nature dynamic behavior. Here, we summarize current understanding on POs, a focus identification quantification, state-of-the-art analytical developments, molecular-level formation mechanisms, chemical transformation pathways, well environmental impacts. We find that interactions SO2 transition metal ions generally fast PO pathways liquid water, lifetimes estimated be minutes hours, while hydrolysis is particularly important α-substituted hydroperoxides. Meanwhile, photolysis thermolysis likely minor sinks POs. These distinctly different fates, such reaction OH radicals, which highlights need understand By summarizing advances remaining challenges investigation propose future research priorities regarding fate,

Язык: Английский

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Reactive aldehyde chemistry explains the missing source of hydroxyl radicals

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Фев. 22, 2024

Abstract Hydroxyl radicals (OH) determine the tropospheric self-cleansing capacity, thus regulating air quality and climate. However, state-of-the-art mechanisms still underestimate OH at low nitrogen oxide high volatile organic compound regimes even considering latest isoprene chemistry. Here we propose that reactive aldehyde chemistry, especially autoxidation of carbonyl peroxy (R(CO)O 2 ) derived from higher aldehydes, is a noteworthy regeneration mechanism overwhelms contribution autoxidation, latter has been proved to largely contribute missing source under condition. As diagnosed by quantum chemical calculations, R(CO)O undergo fast H-migration produce unsaturated hydroperoxyl-carbonyls generate through rapid photolysis. This chemistry could explain almost all unknown sources in areas rich both natural anthropogenic emissions warm seasons, may increasingly impact global capacity future society carbon neutrality scenarios.

Язык: Английский

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Mass Spectrometry Analysis in Atmospheric Chemistry

Analytical Chemistry, Год журнала: 2017, Номер 90(1), С. 166 - 189

Опубликована: Окт. 31, 2017

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTMass Spectrometry Analysis in Atmospheric ChemistryJulia Laskin*†, Alexander Laskin†, and Sergey A. Nizkorodov‡View Author Information† Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States‡ University California, Irvine, California 92697, States*E-mail: [email protected]. Phone: +1-765-494-5464.Cite this: Anal. Chem. 2018, 90, 1, 166–189Publication Date (Web):October 31, 2017Publication History Published online9 November 2017Published inissue 2 January 2018https://pubs.acs.org/doi/10.1021/acs.analchem.7b04249https://doi.org/10.1021/acs.analchem.7b04249review-articleACS PublicationsCopyright © 2017 American Chemical SocietyRequest reuse permissionsArticle Views4888Altmetric-Citations85LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum full text article downloads since 2008 (both PDF HTML) across all institutions individuals. These metrics regularly updated to reflect usage leading up last few days.Citations number other articles citing this article, calculated by Crossref daily. Find more information about citation counts.The Altmetric Attention Score is a quantitative measure attention that research has received online. Clicking on donut icon will load page at altmetric.com with additional details score social media presence for given article. how calculated. Share Add toView InAdd Full Text ReferenceAdd Description ExportRISCitationCitation abstractCitation referencesMore Options onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aerosols,Ionization,Ions,Molecules,Nanoparticles Get e-Alerts

Язык: Английский

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Exploring hydroperoxides in combustion: History, recent advances and perspectives

Progress in Energy and Combustion Science, Год журнала: 2019, Номер 73, С. 132 - 181

Опубликована: Апрель 9, 2019

The aim of this paper is to review recent progress in detection and quantification hydroperoxides, understand their reaction kinetics combustion environments. Hydroperoxides, characterized by an OOH group, are ubiquitous the atmospheric oxidation volatile organic compounds (∼300 K), liquid gas phase fuel components at elevated temperatures (∼400–1000 K). They responsible for two-stage ignition internal engines they play important role formation evolution secondary aerosols atmosphere. introduction outlines importance hydroperoxide chemistry processes. In addition main topic, hydroperoxides also introduced, a more general perspective. second part briefly reviews mechanistic insights systems, including experimental these reactive species before 2010. Since that time significant has been made advanced diagnostic techniques like tunable synchrotron vacuum ultraviolet photoionization mass spectrometry infrared cavity ring-down spectroscopy. third chapter work summarizes experiments measure hydrogen peroxide, alkyl olefinic ketohydroperoxides, complex include as many five oxygen atoms. fourth section details advances understanding involving carboxylic acids diones, well development models O2 mechanism. Finally, challenges discussed, perspectives offered regarding future accurately measuring molecule-specific concentrations respective kinetics.

Язык: Английский

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