Separating Daily 1 km PM_2.5 Inorganic Chemical Composition in China since 2000 via Deep Learning Integrating Ground, Satellite, and Model Data

Environmental Science & Technology, Год журнала: 2023, Номер 57(46), С. 18282 - 18295

Опубликована: Апрель 28, 2023

Fine particulate matter (PM2.5) chemical composition has strong and diverse impacts on the planetary environment, climate, health. These effects are still not well understood due to limited surface observations uncertainties in model simulations. We developed a four-dimensional spatiotemporal deep forest (4D-STDF) estimate daily PM2.5 at spatial resolution of 1 km China since 2000 by integrating measurements species from high-density observation network, satellite retrievals, atmospheric reanalyses, Cross-validation results illustrate reliability sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), chloride (Cl-) estimates, with high coefficients determination (CV-R2) ground-based 0.74, 0.75, 0.71, 0.66, average root-mean-square errors (RMSE) 6.0, 6.6, 4.3, 2.3 μg/m3, respectively. The three components secondary inorganic aerosols (SIAs) account for 21% 20% 14% (NH4+) total mass eastern China; we observed significant reductions 40-43% between 2013 2020, slowing down 2018. Comparatively, ratio SIA increased 7% across except Beijing nearby areas, accelerating recent years. SO42- been dominant component China, although it was surpassed NO3- some e.g., Beijing-Tianjin-Hebei region 2016. SIA, accounting nearly half (∼46%) mass, drove explosive formation winter haze episodes North Plain. A sharp decline concentrations an increase SIA-to-PM2.5 ratios during COVID-19 lockdown were also revealed, reflecting enhanced oxidation capacity particles.

Язык: Английский

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Significant formation of sulfate aerosols contributed by the heterogeneous drivers of dust surface

Atmospheric chemistry and physics, Год журнала: 2022, Номер 22(20), С. 13467 - 13493

Опубликована: Окт. 19, 2022

Abstract. The importance of dust heterogeneous oxidation in the removal atmospheric SO2 and formation sulfate aerosols is not adequately understood. In this study, Fe-, Ti-, Al-bearing components, Na+, Cl−, K+, Ca2+ surface, were discovered to be closely associated with sulfate. Regression models then developed make a reliable prediction reactivity based on particle chemical compositions. Further, recognized gas-phase, aqueous-phase, routes quantitatively assessed kinetically compared by combining laboratory work modelling study. presence 55 µg m−3 airborne dust, accounts for approximately 28.6 % secondary during nighttime, while proportion decreases 13.1 solar irradiation. On drivers (e.g. transition metal constituents, water-soluble ions) are more efficient than surface-adsorbed oxidants H2O2, NO2, O3) conversion SO2, particularly nighttime. Dust offers an opportunity explain missing source severe haze pollution events, its contribution complex environments could even higher current calculation results. Overall, surface responsible significant have profound impacts sulfur cycling.

Язык: Английский

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Recent Progress in Atmospheric Chemistry Research in China: Establishing a Theoretical Framework for the “Air Pollution Complex”

Advances in Atmospheric Sciences, Год журнала: 2023, Номер 40(8), С. 1339 - 1361

Опубликована: Апрель 28, 2023

Atmospheric chemistry research has been growing rapidly in China the last 25 years since concept of "air pollution complex" was first proposed by Professor Xiaoyan TANG 1997. For papers published 2021 on air (only included Web Science Core Collection database were considered), more than 24 000 authored or co-authored scientists working China. In this paper, we review a limited number representative and significant studies atmospheric few years, including (1) sources emission inventories, (2) chemical processes, (3) interactions with meteorology, weather climate, (4) between biosphere atmosphere, (5) data assimilation. The intention not to provide complete all progress made but rather serve as starting point for learning about advances reviewed paper have enabled theoretical framework complex be established, provided robust scientific support highly successful control policies China, created great opportunities education, training, career development many graduate students young scientists. This further highlights that developing low-income countries are heavily affected can benefit from these advances, whilst at same time acknowledging challenges still remain hopefully addressed over next decades.

Язык: Английский

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Significantly Accelerated Photosensitized Formation of Atmospheric Sulfate at the Air–Water Interface of Microdroplets

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(10), С. 6580 - 6590

Опубликована: Март 1, 2024

The multiphase oxidation of sulfur dioxide (SO2) to form sulfate is a complex and important process in the atmosphere. While conventional photosensitized reaction mainly explored bulk medium reported be one drivers trigger atmospheric production, how this scheme functionalizes at air–water interface (AWI) aerosol remains an open question. Herein, employing advanced size-controllable microdroplet-printing device, surface-enhanced Raman scattering (SERS) analysis, nanosecond transient adsorption spectrometer, molecular level theoretical calculations, we revealed previously overlooked interfacial role SO2 humic-like substance (HULIS) aerosol, where 3–4 orders magnitude increase formation rate was speculated cloud relevant-sized particles relative bulk-phase medium. rapid battery reactive oxygen species (ROS) comes from accelerated electron transfer AWI, excited triplet state HULIS (3HULIS*) incomplete solvent cage can readily capture electrons HSO3– way that more efficient than fully blocked by water molecules. This phenomenon could explained significantly reduced desolvation energy barrier required for reagents residing AWI region with shell.

Язык: Английский

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Elucidating the Mechanism on the Transition-Metal Ion-Synergetic-Catalyzed Oxidation of SO₂ with Implications for Sulfate Formation in Beijing Haze

Environmental Science & Technology, Год журнала: 2024, Номер 58(6), С. 2912 - 2921

Опубликована: Янв. 22, 2024

Currently, atmospheric sulfate aerosols cannot be predicted reliably by numerical models because the pathways and kinetics of formation are unclear. Here, we systematically investigated synergetic catalyzing role transition-metal ions (TMIs, Fe3+/Mn2+) in oxidation SO2 O2 on using chamber experiments. Our results showed that effect TMIs is critically dependent aerosol pH due to solubility Fe(III) species sensitive aqueous phase acidity, which effective only under < 3 conditions. The rate 2 orders magnitude larger than bulk solution increases significantly smaller aerosols, suggesting such a synergetic-catalyzed occurs surface. kinetic reaction can described as R = k*[H+]−2.95[Mn(II)][Fe(III)][S(IV)] (pH ≤ 3.0). We found TMI-synergetic-catalyzed dominant pathway Beijing when haze particles very acidic, while heterogeneous NO2 most important weakly acidic. work for first time clarified periods, parameterized into future studies formation.

Язык: Английский

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Important Role of Low Cloud and Fog in Sulfate Aerosol Formation During Winter Haze Over the North China Plain

Geophysical Research Letters, Год журнала: 2024, Номер 51(3)

Опубликована: Фев. 5, 2024

Abstract Sulfate aerosol greatly contributes to wintertime haze pollution in emission‐intensive regions like the North China Plain (NCP) China. Fast sulfate increase and accumulation are usually recorded during winter haze; however, multiphase oxidation of sulfur dioxide (SO 2 ) physical processes affecting near‐surface not fully understood. By combining situ observations numerical simulations, we found that high ratios (>0.6) under heavily polluted conditions associated with low clouds fog over NCP, induced by moist southerly airflow. Thick SO levels NCP provide a reaction environment for production. The production rate cloud water can reach 0.5–1.3 μg m −3 h −1 . results demonstrate vertical mixing generated within surface plays significant role rapid production, highlighting importance understanding cloud‐water pollution.

Язык: Английский

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Aerosol high water contents favor sulfate and secondary organic aerosol formation from fossil fuel combustion emissions

npj Climate and Atmospheric Science, Год журнала: 2023, Номер 6(1)

Опубликована: Окт. 27, 2023

Abstract Fine-particle pollution associated with high sulfate and secondary organic aerosol (SOA) contents still occurs in winter, despite considerable reductions precursor emissions China. The chemical mechanisms involved are consistently acknowledged to be linked water but remain poorly understood. Here, we present findings demonstrating that the synergistic effect of elevated content particles originating from fossil fuel combustion significantly enhanced rapid formation SOAs under humidity conditions during winter northern presence promoted aging process containing elemental carbon (EC) facilitated SOAs. Evidence single reveals an increased potential for SOA primary aerosols (POAs) combustion, increasing water. Under relative exceeding 85%, multiphase oxidation SO 2 by in-particle nitrite/nitrous acid, generated through reactions involving aged EC-containing iron-rich particles, as well aqueous-phase hydroxymethanesulfonate (HMS), led a substantial increase production. This study emphasizes critical role chemistry concerning SOAs, highlighting urgent necessity mitigate combustion.

Язык: Английский

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Role of atmospheric aerosols in severe winter fog over the Indo-Gangetic Plain of India: a case study

Atmospheric chemistry and physics, Год журнала: 2024, Номер 24(11), С. 6635 - 6662

Опубликована: Июнь 6, 2024

Abstract. Winter fog and severe aerosol loading in the boundary layer over northern India, particularly Indo-Gangetic Plain (IGP), disrupt daily lives of millions people region. To better understand role aerosol–radiation (AR) feedback on occurrence, spatial extent, persistence winter fog, as well associated aqueous chemistry IGP, several model simulations have been performed using Weather Research Forecasting coupled with Chemistry (WRF-Chem). While WRF-Chem was able to represent formation for 23–24 December 2017 event central IGP comparison station satellite observations, underestimated PM2.5 concentrations compared Central Pollution Control Board (CPCB) India monitoring network. evaluating composition events we found that quite different from measurements obtained during Fog Experiment (WiFEX) Delhi, secondary aerosols, chloride fraction, being strongly underpredicted (∼ 66.6 %). Missing emission sources (e.g., industry residential burning cow dung trash) processes need be investigated improve model–observation agreement. By investigating a weakens turbulence, lowers height, increases relative humidity (RH) within layer. Factors affecting include loss aerosols through deposition cloud droplets internal mixing absorbing scattering aerosols. Aqueous-phase concentrations, which subsequently affect by both increased mass sizes. With interaction aqueous-phase chemistry, began 1–2 h earlier caused longer duration than when these were not included simulation. The increase RH experiments important it promoted growth size water uptake, increasing content IGP. results this study suggest play an air quality intensity lifetime yet other feedbacks, such aerosol–cloud interactions, quantified.

Язык: Английский

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Rethinking urban haze formation: Atmospheric sulfite conversion rate scales with aerosol surface area, not volume

One Earth, Год журнала: 2024, Номер 7(6), С. 1082 - 1095

Опубликована: Июнь 1, 2024

Aerosols in the atmosphere are effective microreactors for aqueous reactions converting primary pollutants to secondary fine particulate matter (PM2.5). These believed scale with volume of water, such as water deliquesced urban aerosols. Here, using single-particle Raman spectroscopy, we mapped scaling law conversion rate sulfite microdroplets, a key reaction producing sulfate PM2.5 and driving formation China's haze. We show that, droplets below approximately 100 μm, this scales not volume, but droplet surface area, owing kinetic acceleration at air-water interface. Therefore, when linearly extrapolating rates aerosol air-quality models may inaccurately predict rates. predictions likely underpredictions, if adopt parameters measured from laboratory systems, i.e., bulk solutions, surface-area-to-volume ratio much smaller than atmospheric

Язык: Английский

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Sulfate formation through copper-catalyzed SO2 oxidation by NO2 at aerosol surfaces

npj Climate and Atmospheric Science, Год журнала: 2025, Номер 8(1)

Опубликована: Фев. 18, 2025

Язык: Английский

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