ACS Earth and Space Chemistry最新文献

{"title":"Oxidation Kinetics of Alkyl Sulfates and Sulfonates by Sulfate Radical (SO4•–) in the Aqueous Phase: Deactivating Role of Sulfur Functional Groups","authors":"Donger Lai,&nbsp;Thomas Schaefer,&nbsp;Yimu Zhang,&nbsp;Yong Jie Li,&nbsp;Hartmut Herrmann* and Man Nin Chan*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0031310.1021/acsearthspacechem.4c00313","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00313https://doi.org/10.1021/acsearthspacechem.4c00313","url":null,"abstract":"<p >The sulfate radical (SO₄^•–) is a potent oxidant known to efficiently oxidize many organic compounds in the aqueous phase. To date, reactions of SO₄^•– with alkyl sulfates and sulfonates, which are common organosulfur compounds found in atmospheric aerosols and cloud droplets, are not well understood. Here, we employed a laser flash photolysis-long path absorption (LFP-LPA) technique to measure the temperature-dependent oxidation kinetics of organosulfur compounds initiated by SO₄^•– in the aqueous phase. These compounds included five alkyl sulfates, namely, methyl sulfate (MS), ethyl sulfate (ES), octyl sulfate (OS), decyl sulfate (DS), and dodecyl sulfate (SDS), as well as three sulfonates, namely, methanesulfonate (MSA), hydroxymethanesulfonate (HMS), and 2-hydroxyethylsulfonate (HES). Our kinetic data revealed that the second-order rate constants of these organosulfur compounds were in the range of 10³ to 10⁸ L mol^–1 s^–1 and exhibited a positive temperature-dependency across the range of 278 to 318 K. Upon oxidation, the hydrogen abstraction is likely the dominant pathway. Moreover, alkyl sulfates and sulfonates generally exhibit smaller reactivities compared to other organic compounds with the same carbon number, such as alcohols. This reduced reactivity could be explained by the strong electron-withdrawing nature of sulfur functional groups (i.e., −OSO₃^– in alkyl sulfates and −SO₃^– in sulfonates). Among the two sulfur functional groups, −SO₃^– shows a stronger deactivating effect than −OSO₃^–, likely due to the higher charge density of the former. Overall, the findings of this work fill a gap in the understanding of the SO₄^•– oxidation kinetics in organosulfur compounds.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"158–168 158–168"},"PeriodicalIF":2.9,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00313","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Potential Atmospheric Accretion Mechanism: Acid-Catalyzed Hetero-Michael Addition Reactions","authors":"Rebecca Z. Fenselau,&nbsp;Ali R. Alotbi,&nbsp;Caroline B. Lee,&nbsp;Julia S. Cronin,&nbsp;Daniel R. Hill,&nbsp;Jason M. Belitsky and Matthew J. Elrod*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0034210.1021/acsearthspacechem.4c00342","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00342https://doi.org/10.1021/acsearthspacechem.4c00342","url":null,"abstract":"<p >The mechanistic basis for the formation of low volatility secondary organic aerosol (SOA) commonly invokes the formation of larger molecules from two or more smaller molecules, which are generically termed as accretion reactions. The previously unconsidered acid-catalyzed hetero-Michael addition reaction (ACHMAR) is shown to be a potential accretion mechanism route for atmospherically relevant α,β unsaturated carbonyls and alcohols, which are both common atmospheric constituents. The kinetics of ACHMARs for a series of carbonyls and alcohols were measured with bulk aqueous phase experiments using nuclear magnetic resonance (NMR) spectroscopy. The rates of these reactions are shown to be very sensitive to the structures of both the carbonyl (only ketones showed measured reactivity) and the alcohols, with both the less substituted carbonyl and alcohol species exhibiting faster rates of reaction. For example, these results suggest that the major isoprene primary oxidation product methyl vinyl ketone could undergo ACHMARs, while isoprene’s other major oxidation product, methacrolein, is not expected to be similarly reactive. Overall, these results indicate that ACHMARs involving atmospheric α,β ketones are a plausible accretion mechanism in SOA.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"191–200 191–200"},"PeriodicalIF":2.9,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143090399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Catalysis of Ferric Ions and Ferrous Ions on the Reaction of Methylglyoxal and Ammonium Sulfate","authors":"Junyi Yang,&nbsp;Yang Wang,&nbsp;Xuefei Wang* and Yishi Shi*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0024510.1021/acsearthspacechem.4c00245","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00245https://doi.org/10.1021/acsearthspacechem.4c00245","url":null,"abstract":"<p >Secondary brown carbon is an important component of the atmosphere. The contribution of secondary atmospheric brown carbon from the reaction of methylglyoxal (MG) with ammonium sulfate (AS) has been demonstrated in the laboratory. However, the mechanism of the reaction is still unclear, especially influenced by other factors, for example, inorganic salt. In this study, the effect of soluble iron salt on the reaction between MG and AS was investigated through chemical analysis methods, including optical molecular probes. The results indicate that iron sulfate and ferrous sulfate may promote the MG–AS reaction and accelerate the formation of brown carbon. Ferrous sulfate exhibits a higher catalytic activity than ferric sulfate does. Moreover, the reaction mechanism indicates that Fe(II) is the true catalyst, with a rate constant 13 times higher than that of the uncatalyzed reaction, while the catalytic effect of Fe(III) is due to its reduction to Fe(II) by MG. In addition, the complex of Fe(II) and MG in the aqueous phase was identified.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"119–125 119–125"},"PeriodicalIF":2.9,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143090382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enrichment of Potassium During Simulated Weathering of Chloride Evaporites","authors":"Md. Rumman-Uz Zaman,&nbsp;Daniel J. Ranciglio,&nbsp;Brittany E.W. Mooney and Paul J. Bracher*,&nbsp;","doi":"10.1021/acsearthspacechem.3c0037610.1021/acsearthspacechem.3c00376","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.3c00376https://doi.org/10.1021/acsearthspacechem.3c00376","url":null,"abstract":"<p >This paper reports a simple, prebiotically feasible process for the enrichment of potassium salts from the seepage of water through evaporated mixtures of chlorides thought to dominate Earth’s early ocean. When water passes through a mixture of NaCl and KCl, the solid dissolves and the initial eluate contains NaCl:KCl in a 2.4:1 molar ratio, consistent with the invariant point of the NaCl–KCl–H₂O ternary system. The ratio of eluted NaCl:KCl remains constant until the supply of one of the salts in the solid phase is exhausted and the eluate transitions to a saturated solution of the remaining salt. If the initial mixture of salts contains &lt;2.4:1 NaCl:KCl, a pure solution of KCl will eventually elute from the system. Similar behavior extends to the weathering observed in NaCl–KCl–MgCl₂–CaCl₂–H₂O mixtures. For this quinary system, the eluate initially contains NaCl:KCl:MgCl₂:CaCl₂ in an approximate ratio of 1:1.6:4:4. CaCl₂ and MgCl₂ are depleted rapidly relative to NaCl and KCl, and once the calcium and magnesium are exhausted, the system returns to the behavior observed of a NaCl–KCl–H₂O ternary system. The universal enrichment of potassium ions by cells─driven by ion transporters and channels─suggests that potassium is critical to life as-we-know-it and was possibly a biochemical relic of the environment where life originated. The weathering experiments described here collectively demonstrate a potential mechanism for the enrichment of potassium salts that could have transpired naturally on the Prebiotic Earth to generate the sort of potassium-rich environment that may have fostered early life on the planet.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"8–15 8–15"},"PeriodicalIF":2.9,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143089196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-Crystal Elasticity of α-Hydroquinone─An Analogue for Organic Planetary Materials","authors":"Jin S. Zhang*,&nbsp;Wen-Yi Zhou,&nbsp;Tuan H. Vu,&nbsp;Robert Hodyss and Xinting Yu,&nbsp;","doi":"10.1021/acsearthspacechem.4c0032210.1021/acsearthspacechem.4c00322","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00322https://doi.org/10.1021/acsearthspacechem.4c00322","url":null,"abstract":"<p >In this study, we measured the single-crystal elasticity of α-hydroquinone at ambient conditions using Brillouin spectroscopy to assess the feasibility of this technique for studying the mechanical properties of organic ices in the outer solar system. In this study, α-hydroquinone serves as an ambient temperature analogue for low-temperature organic ices on Titan and other solar system bodies. We found that a satisfactory Brillouin spectrum can be obtained in less than 5 min of experimental time with negligible damage to the sample. The best fit single-crystal elastic moduli of α-hydroquinone were determined as <i>C</i>₁₁ = 13.67(8) GPa, <i>C</i>₃₃ = 10.08(6) GPa, <i>C</i>₄₄ = 4.54(5) GPa, <i>C</i>₁₂ = 6.9(7) GPa, <i>C</i>₁₃ = 7.02(7) GPa, <i>C</i>₁₄ = 0.54(4) GPa, <i>C</i>₂₅ = 0.51(9) GPa, and <i>C</i>₆₆ = (<i>C</i>₁₁ – <i>C</i>₁₂)/2 = 3.4(3) GPa, with bulk modulus <i>K</i>_S = 8.7(2) GPa and shear modulus <i>G</i> = 3.4(3) GPa. These results demonstrate that Brillouin spectroscopy is a powerful tool for characterizing the elastic properties of organic materials. The elastic properties of organic ices can be broadly applied to understand planetary surface processes and also aid in evaluating the feasibility and technical readiness of future lander, sampling, and rover missions in the outer solar system.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"1–7 1–7"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00322","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143087775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-Crystal Elasticity of α-Hydroquinone-An Analogue for Organic Planetary Materials.","authors":"Jin S Zhang, Wen-Yi Zhou, Tuan H Vu, Robert Hodyss, Xinting Yu","doi":"10.1021/acsearthspacechem.4c00322","DOIUrl":"10.1021/acsearthspacechem.4c00322","url":null,"abstract":"<p><p>In this study, we measured the single-crystal elasticity of α-hydroquinone at ambient conditions using Brillouin spectroscopy to assess the feasibility of this technique for studying the mechanical properties of organic ices in the outer solar system. In this study, α-hydroquinone serves as an ambient temperature analogue for low-temperature organic ices on Titan and other solar system bodies. We found that a satisfactory Brillouin spectrum can be obtained in less than 5 min of experimental time with negligible damage to the sample. The best fit single-crystal elastic moduli of α-hydroquinone were determined as <i>C</i> ₁₁ = 13.67(8) GPa, <i>C</i> ₃₃ = 10.08(6) GPa, <i>C</i> ₄₄ = 4.54(5) GPa, <i>C</i> ₁₂ = 6.9(7) GPa, <i>C</i> ₁₃ = 7.02(7) GPa, <i>C</i> ₁₄ = 0.54(4) GPa, <i>C</i> ₂₅ = 0.51(9) GPa, and <i>C</i> ₆₆ = (<i>C</i> ₁₁ - <i>C</i> ₁₂)/2 = 3.4(3) GPa, with bulk modulus <i>K</i> _S = 8.7(2) GPa and shear modulus <i>G</i> = 3.4(3) GPa. These results demonstrate that Brillouin spectroscopy is a powerful tool for characterizing the elastic properties of organic materials. The elastic properties of organic ices can be broadly applied to understand planetary surface processes and also aid in evaluating the feasibility and technical readiness of future lander, sampling, and rover missions in the outer solar system.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"1-7"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11744926/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142996044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron Enrichment Mechanism in Granular Iron Formation (GIF) of the Wuzhiling Formation, Songshan Group, North China Craton: Implications for Metallogeny","authors":"Boyang Xu,&nbsp;Deshun Zheng*,&nbsp;Fengbo Sun,&nbsp;Bin Tang,&nbsp;Xin Wang and Ting Li,&nbsp;","doi":"10.1021/acsearthspacechem.4c0022010.1021/acsearthspacechem.4c00220","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00220https://doi.org/10.1021/acsearthspacechem.4c00220","url":null,"abstract":"<p >The extensive Paleoproterozoic iron formations (IFs) distributed across the North China Craton serve as ideal proxies for understanding the redox variations in paleo-oceans before and after the Great Oxidation Event (GOE). Here, we present a comprehensive analysis of the lithofacies, mineralogy, and geochemical characteristics of the granular iron formation (GIF) within the Paleoproterozic Wuzhiling Formation of the Songshan Group in the southern North China Craton. Our findings reveal that the GIF represents a chemical sedimentary rock, precipitated within a water column characterized by layered oxygen-depleted to suboxic conditions. The protolith sediments of the GIF in the Wuzhiling Formation are hypothesized to have comprised quartz-coated hematite microparticles, along with precursor deposits of aragonite and hexagonal iron oxides, commonly referred to as green rust. Mineralogically, the GIF is predominantly composed of quartz and hematite, with the iron content attributed to the weathering processes of continental crustal materials, the influence of low-temperature hydrothermal fluids, and the incorporation of iron from seawater. During the GOE, a pivotal transition in Earth’s history, the (Pr/Yb) ratios normalized to PAAS (Post-Archean Australian Shale) standards exhibit increased dispersion, accompanied by a gradual decrease in the Y/Ho ratios. These geochemical shifts suggest a pronounced alteration in the ancient marine environment, transitioning from a monolithic reducing state to a more complex redox stratification within the seawater after the GOE. In summary, this study contributes to the reconstruction of paleo-ocean redox conditions around the GOE, providing evidence for the re-establishment of Precambrian paleoenvironmental conditions.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"92–105 92–105"},"PeriodicalIF":2.9,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143087019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical Spectroscopy and Photochemistry of Silicon Oxide Cations: The Case of Triatomic Si2O+ and SiO2+","authors":"Taarna Studemund,&nbsp;Kai Pollow,&nbsp;Marko Förstel,&nbsp;Emil Mickein,&nbsp;Alexander A. Breier and Otto Dopfer*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0032610.1021/acsearthspacechem.4c00326","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00326https://doi.org/10.1021/acsearthspacechem.4c00326","url":null,"abstract":"<p >Small silicon oxide compounds are considered crucial in the formation and evolution of stardust, particularly particles with silica and silicate cores. Thus, detailed information on the geometry, energy, electronic structure, reactivity, and photochemistry of small silicon oxides is essential for unraveling the fundamental mechanisms involved in the production and processing of stardust. Herein, the optical spectra of size-selected triatomic Si₂O⁺ and SiO₂⁺ cations are obtained in the range 289.9–709.4 nm (1.75–4.28 eV, 14,100–34,500 cm^–1) by means of electronic photodissociation (EPD) in a tandem mass spectrometer coupled to a laser vaporization source. The EPD spectra are assigned by comparison to density functional theory calculations. The EPD spectrum of Si₂O⁺ observed in the lowest-energy Si⁺ fragment ion channel is characterized by two band systems <b>A</b> and <b>B</b> with maxima observed at 25,202(5) and 30,609(5) cm^–1. Bands <b>A</b> and <b>B</b> are assigned to transitions into the excited D₃(²B₂) and D₆(²B₂) doublet electronic states of the bent isomer <b>II</b> with <i>C</i>_2v symmetry. Resolved vibronic structure of band <b>B</b> is attributed to anharmonic progressions of the symmetric stretching and bending modes, ω₁ = 707(2) and ω₂ = 804(3) cm^–1. The predicted more stable linear isomer <b>I</b> with <i>D</i>_∞h symmetry (Δ<i>E</i>₀ = 0.23 eV) does not have any allowed transition expected in the spectral range investigated and is not observed. In line with the computational prediction, the EPD spectra measured for linear SiO₂⁺ do not reveal any electronic transition, because of its vanishing absorption cross section in the considered spectral range.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"178–190 178–190"},"PeriodicalIF":2.9,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00326","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143086519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and Structure of Acetylenic Acylium Cations","authors":"Dirk Hollenwäger*,&nbsp;Dominik Leitz,&nbsp;Alexander Nitzer,&nbsp;Valentin Bockmair and Andreas J. Kornath,&nbsp;","doi":"10.1021/acsearthspacechem.4c0025310.1021/acsearthspacechem.4c00253","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00253https://doi.org/10.1021/acsearthspacechem.4c00253","url":null,"abstract":"<p >Acetylenedicarbonyl fluoride and propiolyl fluoride were investigated in the Lewis acidic medium consisting of SbF₅/CF₃CH₂F. The acetylenic acyl cations are characterized by vibrational spectroscopy, NMR spectroscopy, and single-crystal X-ray diffraction. The protonated species of propiolyl fluoride decomposes in a few hours at −78 °C in a dynamic vacuum which leads to the formation of the corresponding acylium cation. The room-temperature stable methylated acyl fluoride was prepared in the ternary system CH₃F/SbF₅/SO₂. The experimental data are discussed together with quantum chemical calculations on the M06-2X/aug-cc-pVTZ level of theory.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"126–133 126–133"},"PeriodicalIF":2.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143086752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aircraft Measurements from a U.S. Western Wildfire Demonstrating Day and Night Differences in the Chemical Composition and Optical Properties of Biomass Burning Aerosols and Their Atmospheric Evolution","authors":"Felipe A. Rivera-Adorno,&nbsp;Lisa Azzarello,&nbsp;Michael A. Robinson,&nbsp;Zachary C. J. Decker,&nbsp;Rebecca A. Washenfelder,&nbsp;Katherine Hayden,&nbsp;Alessandro Franchin,&nbsp;Christopher D. Holmes,&nbsp;Cora J. Young,&nbsp;Carley D. Fredrickson,&nbsp;Brett Palm,&nbsp;Chris Schmidt,&nbsp;Amber Soja,&nbsp;Emily Gargulinski,&nbsp;Steven S. Brown,&nbsp;Ann M. Middlebrook and Alexander Laskin*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0021510.1021/acsearthspacechem.4c00215","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00215https://doi.org/10.1021/acsearthspacechem.4c00215","url":null,"abstract":"<p >The composition and transformations of biomass burning aerosols (BBA) have been measured onboard the NOAA Twin Otter research aircraft during the Fire Influence on Regional to Global Environments and Air Quality field study. We analyze real-time aerosol mass spectrometry measurements across three flights during the afternoon, late afternoon, and night of August 28, 2019, for one midsized wildfire. Analysis of several metrics showed that the aerosol composition and optical properties varied depending on the burning conditions at the fire zone and the time of day the BBA was emitted, with substantial variations in the available sunlight. The total aerosol mass loadings were dominated by organic components with a much smaller contribution from inorganic species. A gradual buildup of organic material was observed during the afternoon as the plume aged, indicating the condensation of photochemically formed low-volatility oxidized organic compounds. Highly hygroscopic ammonium nitrate was the main inorganic component, suggesting potential water content in BBA particles and the likelihood of their aqueous-phase reactivity. Depletions of particle-phase NO₃^– and Cl^– relative to carbon monoxide were observed in the late afternoon and nighttime plumes, respectively, aligning with known gas-particle partitioning thermodynamics and the heterogeneous chemistry of dissolved nitrate and chloride. The wavelength-dependent light absorption by aerosol species was higher for the plume sampled at night and showed no significant changes with plume age, despite observed trends in composition and mass downwind. These differences in particle composition and optical properties demonstrate that the processes involved in BBA aging are not uniform for the same wildfire over the course of the day and depend highly on when the BBA was emitted, as well as the burning phase at the emissions source.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 1","pages":"64–75 64–75"},"PeriodicalIF":2.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143085615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}