Multiphase reactivity of polycyclic aromatic hydrocarbons is driven by phase separation and diffusion limitations

Proceedings of the National Academy of Sciences, Год журнала: 2019, Номер 116(24), С. 11658 - 11663

Опубликована: Май 29, 2019

Significance Polycyclic aromatic hydrocarbons (PAHs) are among the most prominent toxic compounds in air. Heterogeneous reactions involving O 3 can change toxicity of PAHs, but reaction mechanism and kinetics remain to be elucidated. Based on new experiments combined with state-of-the-art kinetic thermodynamic models, we show that phase separation plays a critical role ozonolysis PAHs mixed secondary organic aerosols oils. Ozonolysis products separate form viscous surface crusts, which protect underlying from prolong their chemical lifetime. These results have significant implications for outdoor indoor air quality by affecting PAH long-range transport fate environments.

Язык: Английский

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Lifecycle of light-absorbing carbonaceous aerosols in the atmosphere

npj Climate and Atmospheric Science, Год журнала: 2020, Номер 3(1)

Опубликована: Окт. 21, 2020

Abstract Light-absorbing carbonaceous aerosols (LACs), including black carbon and light-absorbing organic (brown carbon, BrC), have an important role in the Earth system via heating atmosphere, dimming surface, modifying dynamics, reducing snow/ice albedo, exerting positive radiative forcing. The lifecycle of LACs, from emission to atmospheric evolution further deposition, is key their overall climate impacts uncertainties determining hygroscopic optical properties, burden, interactions with clouds, deposition on snowpack. At present, direct observations constraining some processes during LACs (e.g., between hydrometeors) are rather limited. Large inconsistencies directly measured LAC properties those used for model evaluations also exist. Modern models starting incorporate detailed aerosol microphysics evaluate transformation rates water solubility, chemical composition, phases which shown improved performance. However, process-level understanding modeling still poor particularly BrC, yet be sufficiently assessed due lack global-scale measurements. Appropriate treatments size- composition-resolved that influence both aerosol–cloud expected advance quantification light absorption system. This review summarizes recent advances up-to-date knowledge highlighting essential issues where measurements need improvement.

Язык: Английский

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Radical chemistry in oxidation flow reactors for atmospheric chemistry research

Chemical Society Reviews, Год журнала: 2020, Номер 49(9), С. 2570 - 2616

Опубликована: Янв. 1, 2020

We summarize the studies on chemistry in oxidation flow reactor and discuss its atmospheric relevance.

Язык: Английский

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A review of aerosol chemistry in Asia: insights from aerosol mass spectrometer measurements

Environmental Science Processes & Impacts, Год журнала: 2020, Номер 22(8), С. 1616 - 1653

Опубликована: Янв. 1, 2020

Aerosol mass spectrometer has been widely deployed in Asia for real-time characterization of aerosol chemistry, and significantly improved our understanding the sources, properties, formation processes aerosols a complex environment.

Язык: Английский

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Tropospheric and stratospheric wildfire smoke profiling with lidar: mass, surface area, CCN, and INP retrieval

Atmospheric chemistry and physics, Год журнала: 2021, Номер 21(12), С. 9779 - 9807

Опубликована: Июнь 29, 2021

Abstract. We present retrievals of tropospheric and stratospheric height profiles particle mass, volume, surface area, number concentrations in the case wildfire smoke layers as well estimates smoke-related cloud condensation nuclei (CCN) ice-nucleating (INP) from backscatter lidar measurements on ground space. Conversion factors used to convert optical into microphysical properties play a central role data analysis, addition extinction-to-backscatter ratios required obtain extinction coefficients. The set needed conversion parameters for is derived AERONET observations major events, e.g., western Canada August 2017, California September 2020, southeastern Australia January–February 2020 long-term Amazon region, southern Africa, Southeast Asia. new analysis scheme applied CALIPSO plumes over United States ground-based observation Punta Arenas, Chile, aged Australian stratosphere January 2020. These studies show potential spaceborne lidars document large-scale long-lasting events detail thus provide valuable information climate, cloud, air chemistry modeling efforts performed investigate atmospheric system.

Язык: Английский

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Tropical and Boreal Forest – Atmosphere Interactions: A Review

Tellus B, Год журнала: 2022, Номер 74(1), С. 24 - 24

Опубликована: Март 25, 2022

This review presents how the boreal and tropical forests affect atmosphere, its chemical composition, function, further that affects climate and, in return, ecosystems through feedback processes. Observations from key tower sites standing out due to their long-term comprehensive observations: The Amazon Tall Tower Observatory Central Amazonia, Zotino Siberia, Station Measure Ecosystem-Atmosphere Relations at Hyytiäla Finland. is complemented by short-term observations networks large experiments. discusses atmospheric chemistry observations, aerosol formation processing, physiochemical aerosol, cloud condensation nuclei properties finds surprising similarities important differences two ecosystems. concentrations are similar, particularly concerning main components, both dominated an organic fraction, while ecosystem has generally higher of inorganics, influence long-range transported air pollution. emissions biogenic volatile compounds isoprene monoterpene regions, respectively, being precursors fraction. modeling studies show change deforestation such carbon hydrological cycles Amazonia changing neutrality precipitation downwind. In Africa, so far maintaining sink. It urgent better understand interaction between these major ecosystems, climate, which calls for more observation sites, providing data on water, carbon, other biogeochemical cycles. essential finding a sustainable balance forest preservation reforestation versus potential increase food production biofuels, critical services global stability. Reducing warming vital forests.

Язык: Английский

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Ice‐Nucleating Particles That Impact Clouds and Climate: Observational and Modeling Research Needs

Reviews of Geophysics, Год журнала: 2022, Номер 60(2)

Опубликована: Апрель 21, 2022

Abstract Atmospheric ice‐nucleating particles (INPs) play a critical role in cloud freezing processes, with important implications for precipitation formation and radiative properties, thus weather climate. Additionally, INP emissions respond to changes the Earth System climate, example, desertification, agricultural practices, fires, therefore may introduce climate feedbacks that are still poorly understood. As knowledge of nature origins INPs has advanced, regional global weather, system models have increasingly begun link ice processes model‐simulated aerosol abundance types. While these recent advances exciting, coupling simulated also makes physics simulations susceptible uncertainties simulation INPs, which constrained by observations. Advancing predictability reasonable spatiotemporal resolution will require an increased focus on research bridges measurement modeling communities. This review summarizes current state identifies gaps from both observational perspectives. In particular, we emphasize needs two key areas: (a) closure between quantities (b) skillful within existing models. We discuss various particle types briefly challenges faced understanding impacts present‐day Finally, identify priority directions observations improve their interactions System.

Язык: Английский

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Atmospheric ice nucleation

Nature Reviews Physics, Год журнала: 2023, Номер 5(4), С. 203 - 217

Опубликована: Март 23, 2023

Язык: Английский

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Formation of secondary organic aerosol from wildfire emissions enhanced by long-time ageing

Nature Geoscience, Год журнала: 2024, Номер 17(2), С. 124 - 129

Опубликована: Янв. 9, 2024

Язык: Английский

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Semivolatile POA and parameterized total combustion SOA in CMAQv5.2: impacts on source strength and partitioning

Atmospheric chemistry and physics, Год журнала: 2017, Номер 17(18), С. 11107 - 11133

Опубликована: Сен. 20, 2017

Abstract. Mounting evidence from field and laboratory observations coupled with atmospheric model analyses shows that primary combustion emissions of organic compounds dynamically partition between the vapor particulate phases, especially as near-source dilute cool to ambient conditions. The most recent version Community Multiscale Air Quality 5.2 (CMAQv5.2) accounts for semivolatile partitioning gas-phase aging these aerosol (POA) consistent experimentally derived parameterizations. We also include a new surrogate species, potential secondary (pcSOA), which provides representation (SOA) anthropogenic sources could be missing current chemical transport predictions. reasons this mass likely following: (1) unspeciated intermediate volatility compound (SVOC IVOC, respectively) inventories, (2) multigenerational products known SOA precursors (e.g., toluene, alkanes), (3) underestimation yields due wall losses in smog chamber experiments, (4) reversible compounds–water interactions and/or aqueous-phase processing emissions. CMAQ predicts spatially averaged contribution pcSOA OA surface concentrations continental United States 38.6 23.6 % 2011 winter summer, respectively. Whereas many past modeling studies focused on particular measurement campaign, season, location, or configuration, we endeavor evaluate important uncertain parameters comprehensive set States-based runs using multiple horizontal scales (4 12 km), mechanisms, seasons years. POA improves predictions hourly over traditional nonvolatile at sites during campaigns southern California (CalNex, May–June 2010), northern (CARES, June southeast US (SOAS, 2013; SEARCH, January July, 2011). Model improvements manifest better correlations correlation coefficient Pasadena night increases 0.38 0.62) reductions underprediction photochemically active afternoon period bias −5.62 −2.42 µg m−3). Daily routine-monitoring networks simulations (CONUS) show modest improvement winter, mean biases reducing 1.14 0.73 m−3, but less change summer when decreases evaporation were similar magnitude added mass. Because model-performance realized by including relatively simple approach is more-complicated parameterizations formation aging, recommend caution applying approaches they currently rely numerous parameters. optimized performance lead higher than observed CONUS evaluation. This may any variations real different regions time periods, too-high other are larger domain, issues such loss processes. discrepancy regionally temporally dependent driven interferences factors like varying regimes.

Язык: Английский

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