Environmental Science Atmospheres, Journal Year: 2023, Volume and Issue: 3(10), P. 1384 - 1395
Published: Jan. 1, 2023
This work establishes the determination of uptake coefficient HO 2 onto a series inorganic aerosols by LP-LIF.
Language: Английский
Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown
Published: Jan. 17, 2025
Hydroxyl radical (·OH) plays a crucial role in atmospheric chemistry, regulating the oxidative potential and aerosol composition. This study reveals an unprecedented source of ·OH atmosphere: mineral dust-bearing microdroplet aerosols. We demonstrate that Kaolin clay particles aerosols trigger rapid production upon solar irradiation, with rates reaching order at least 10-3 M s-1. rate is several orders magnitude higher than bulk phase (2.4 × 10-11 s-1) previously known pathways. On this basis, surface-based interfacial estimated to be 8.9 10-5 mol m-2 s-1 air-water-solid interface 1 μm sized particles. The enhanced formation attributed unique features interfaces, where lifespan photoinduced holes was significantly increased due presence strong electric fields air-water interface. further investigated impacts various environmental factors properties on production, including light intensity, relative humidity, particle size, pH. Our findings provide new insights into photochemical processes mediated by aerosols, which are important contributors atmosphere. work advances our understanding chemistry its profound lasting implications for air quality climate.
Language: Английский
Citations
1
The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 856, P. 158895 - 158895
Published: Sept. 18, 2022
Language: Английский
Citations
31
Biogeosciences, Journal Year: 2025, Volume and Issue: 22(1), P. 243 - 256
Published: Jan. 13, 2025
Abstract. Microorganisms in the atmosphere comprise a small fraction of Earth's microbiome. A significant portion this aeromicrobiome consists bacteria that typically remain airborne for few days before being deposited. Unlike other spheres (e.g., litho-, hydro-, phyllo-, cryospheres), atmospheric are aerosolized, residing individual particles and separated from each other. In atmosphere, encounter chemical physical conditions affect their stress levels survival. This article goes beyond previous overviews by placing these context fundamental microphysical concepts related to aerosols. We provide ranges water amounts surrounding bacterial cells both inside outside clouds suggest volumes cloud droplets lead nutrient oxidant limitations. may result greater limitation but lower oxidative than previously thought. Various factors enhance or reduce microbial oxidative, osmotic, UV-induced), affecting functioning survival bacteria. illustrate could impact under polluted conditions, indicating conclusions about role pollutants directly causing changes abundance can be erroneous. The perspectives presented here aim motivate future experimental modeling studies disentangle complex interplay with Such will help comprehensively characterize modifying Earth' microbiome, which regulates stability global ecosystems biodiversity.
Language: Английский
Citations
0
ACS Earth and Space Chemistry, Journal Year: 2025, Volume and Issue: 9(3), P. 689 - 698
Published: Feb. 25, 2025
Iron contained in atmospheric aerosol particles can form complexes with organic ligands and initiate photochemical reactions that alter the composition physicochemical properties of particles. Depending on temperature humidity, exist different phase states, which affects reactant diffusivity chemical reaction rates. We performed coated-wall flow-tube experiments using citric acid films doped iron as proxies for secondary aerosols. quantified CO2 production under UV irradiation a function time relative humidity (RH) observed pronounced decrease decreasing RH. The kinetic multilayer model surface bulk chemistry (KM-SUB) Monte Carlo-based global optimization method were applied to all measured data determine underlying effects mass transport reactions. analysis revealed after an initial rapid reaction, photooxidation becomes limited by reoxidation FeII. Under dry conditions (RH < 65%), FeII is kinetically supply O2, slow diffusion viscous matrix leads anoxia interior film. At high > 85%), limitations cease, resulting full O2 saturation, oxidants. Reactive oxygen species play key role thus perpetuating chemistry. A single molecule triggers redox cascade from HO2, H2O2, OH, leading ≈3 cycles FeII/FeIII pair. Our parameters provide new insights constraints interplay microphysical aging mixed organic–inorganic particles, may influence their air quality, climate, public health.
Language: Английский
Citations
0
Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(5)
Published: March 3, 2025
Abstract Naturally occurring chlorate (ClO 3 − ) has been observed on Earth and potentially plays important roles in hydrology mineralogy Mars. However, natural sources of are uncertain. Here, we quantify the importance atmospheric chlorate. We use GEOS‐Chem, a global three‐dimensional chemical transport model, to simulate formation, photochemical loss, transport, deposition present‐day Earth. also develop method estimate 17 O‐excess (∆ O) 36 Cl‐to‐total‐Cl ratio ( Cl/Cl) interpret isotopic composition accumulated desert soils. The model predicts that gas‐phase chemistry can produce 15 Gg Cl year −1 chloric acid (HClO ), which predominantly is taken up by aerosols form particulate Comparing with observations suggests undergoes loss atmosphere, controls amount reaching Earth's surface. show initial ∆ O acquires during formation would be erased rapidly acidic due exchange oxygen atoms water. analysis Cl/Cl does not preclude partial stratospheric origin for deposits Atacama Desert. In Death Valley, aqueous‐phase oxidation oxychlorine species anthropogenic activities have greater influence. Our findings highlight need more laboratory measurements its reactivity conditions. Atmospheric should considered future studies
Language: Английский
Citations
0
Atmospheric Environment, Journal Year: 2024, Volume and Issue: 329, P. 120536 - 120536
Published: April 26, 2024
Language: Английский
Citations
2
Environmental Science Atmospheres, Journal Year: 2024, Volume and Issue: 4(7), P. 813 - 829
Published: Jan. 1, 2024
The first measurements of HO 2 uptake coefficients ( γ ) onto suspended aerosol particles as a function temperature are reported in the range 314 K to 263 K.
Language: Английский
Citations
2
Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(14), P. 8263 - 8275
Published: July 22, 2024
Abstract. Each year, commercial ships emit over 1.67 Tg of particulate matter (PM) pollution into the atmosphere. These rely on combustion heavy fuel oil, which contains high levels sulfur, large aromatic organic compounds, and metals. Vanadium is one metals most commonly associated with oil often used as a tracer for PM from ship exhaust. Previous studies have suggested that vanadium-containing has impacts human health climate due to its toxicological cloud-formation properties, respectively; however, distribution in atmosphere not fully understood, limits our ability quantify environmental implications emitted by ships. Here, we present data obtained Particle Analysis Laser Mass Spectrometry (PALMS) instrument NASA DC-8 aircraft during 2016–2018 Atmospheric Tomography Mission (ATom) show ∼ 1 % accumulation mode particles measured marine boundary layer central Pacific Atlantic oceans contain vanadium. measurements, were made without targeting plumes, suggest widespread Furthermore, observed exhaust at altitudes up 13 km, demonstrates all are immediately removed via wet deposition processes. In addition, using laboratory calibrations, determined can few weight percent This study furthers understanding both chemical composition ships, will allow us better constrain climate, health, air quality these particle types future. We note collected prior 2020 International Maritime Organization (IMO) sulfur regulation stand reference how emissions evolved light regulations.
Language: Английский
Citations
2
Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(14), P. 9978 - 9987
Published: June 25, 2022
Particulate matter (PM) and gaseous hydrogen peroxide (H2O2) interact ubiquitously to influence atmospheric oxidizing capacity. However, quantitative information on H2O2 loss its fate urban aerosols remain unclear. This study investigated the kinetics of heterogeneous reactions PM2.5 explored how these processes are affected by various experimental conditions (i.e., relative humidity, temperature, concentration). We observed a persistent uptake (with coefficients (γ) 10-4-10-3) exacerbated aerosol liquid water confirming critical role water-assisted chemical decomposition during process. A positive correlation between γ values ratio dissolved iron concentration suggests that Fenton catalytic may be an important pathway for conversion under dark conditions. Furthermore, basis kinetic data gained, parameterization was developed applied into box model. The good agreement simulated measured uncovered significant plays in sink atmosphere. These findings suggest composition-dependent particle reactivity toward should considered models elucidating environmental health effects ambient aerosols.
Language: Английский
Citations
11
The Journal of Physical Chemistry A, Journal Year: 2022, Volume and Issue: 126(44), P. 8295 - 8304
Published: Nov. 1, 2022
Chemical models that describe the atmospheric multiphase (gas/aqueous) system often include detailed kinetic and mechanistic schemes describing chemical reactions in both phases. The present study explores importance of properties including composition droplet populations, such as pH value iron only a few droplets, well size their distribution. It is found assumption evenly distributed all cloud droplets leads to an underestimate by up 1 order magnitude OH concentrations aqueous phase, whereas predicted iron(II)/iron(total) ratio overestimated factor 2. While sulfate mass formed not largely affected any assumptions, secondary organic aerosol varies magnitude. This sensitivity reveals chemistry model studies should focus on mechanism development but also careful considerations comprehensively system.
Language: Английский
Citations
7