Festive fireworks in Delhi: A major source of elemental aerosols established through dispersion normalized PMF in a multiyear study

Atmospheric Environment, Год журнала: 2024, Номер 323, С. 120394 - 120394

Опубликована: Фев. 10, 2024

Язык: Английский

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Influence of Relative Humidity and Composition on PM_2.5 Phases in Northeast Asia

ACS Earth and Space Chemistry, Год журнала: 2024, Номер 8(4), С. 788 - 797

Опубликована: Апрель 2, 2024

In Northeast Asia, the elevated levels of fine particulate matter (PM2.5) are an environmental concern, yet their physicochemical properties have been poorly characterized. Herein, we determined phase states PM2.5 in 92 filter samples collected from four different cities─Beijing, Seoul, Seosan, and Ulaanbaatar─during 2020–2022, within a temperature range ∼290–293 K. We noted distinct trend boundary relative humidity (RH) liquid semisolid phases these samples. As inorganic fraction increased, RH decreased, whereas that increased. This behavior was strongly influenced by chemical composition PM2.5. By incorporating ambient data each city, estimated prevalent planetary layer Asia. Our findings revealed dominant urban areas were semisolid. Additionally, showed critical threshold based on aerosol water content (ALWC) PM2.5: primarily for ALWC/PM2.5 ratios ≥∼0.5 predominantly <∼0.5. These insights could contribute to better understanding mechanisms underlying pollution

Язык: Английский

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Characteristics of Haze Pollution Events During Biomass Burning Period at an Upwind Site of Delhi

Journal of Geophysical Research Atmospheres, Год журнала: 2025, Номер 130(7)

Опубликована: Апрель 8, 2025

Abstract The National Capital Region (NCR) of Delhi frequently experiences severe haze episodes during the post‐monsoon and winter months, driven by long‐range transport biomass burning aerosols, local emissions, unfavorable meteorological conditions. However, observational studies tracing these pollution along pathway to are lacking. This study investigates at an upwind site in Sonipat using advanced instrumentation October 25 15 November 2023, encompassing Diwali events. Sudden spikes pollutants caused haze, temporary reductions due rainfall, a resurgence Diwali. Two major were identified, with particulate matter (PM 2.5 ) levels exceeding 300 μg/m 3 . Organics dominated composition based PM (C‐PM followed Black Carbon (BC), jointly accounting for ∼80% total mass all episodes, secondary inorganics contributed minimally. Limited day‐night variations low contribution suggested minimal photochemical activity formation. Elevated tracers emission ratios indicated aged, oxidized aerosols from crop residue Punjab Haryana, supported fire count data 72‐hr backward trajectory analysis. Regional meteorology, including shallow atmospheric boundary layer (ABL) wind speeds, hindered pollutant dispersion, leading accumulation prolonged haze. By integrating analysis, factors, dynamics, this provides critical insights into formation, emphasizing need targeted mitigation strategies, such as stricter controls improved management, address its health risks effectively.

Язык: Английский

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Thermodynamical framework for effective mitigation of high aerosol loading in the Indo-Gangetic Plain during winter

Scientific Reports, Год журнала: 2023, Номер 13(1)

Опубликована: Авг. 22, 2023

Abstract The Indo-Gangetic Plain (IGP) experiences severe air pollution every winter, with ammonium chloride and nitrate as the major inorganic fractions of fine aerosols. Many past attempts to tackle in IGP were inadequate, they targeted a subset primary pollutants an environment where majority particulate matter burden is secondary nature. Here, we provide new mechanistic insight into aerosol mitigation by integrating ISORROPIA-II thermodynamical model high-resolution simultaneous measurements precursor gases A mathematical framework explored investigate complex interaction between hydrochloric acid (HCl), nitrogen oxides (NO x ), ammonia (NH 3 liquid water content (ALWC). Aerosol acidity (pH) ALWC emerge governing factors that modulate gas-to-particle phase partitioning mass loading Six "sensitivity regimes" defined, PM 1 2.5 fall "HCl HNO sensitive regime", emphasizing HCl reductions would be most effective pathway for IGP, which ammonia-rich during winter. This study provides evidence abatement should not based on their descending concentrations but instead sensitivity high loading.

Язык: Английский

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Study of secondary organic aerosol formation and aging using ambient air in an oxidation flow reactor during high pollution events over Delhi

Environmental Research, Год журнала: 2024, Номер 251, С. 118542 - 118542

Опубликована: Фев. 23, 2024

Язык: Английский

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Current challenges in the visibility improvement of urban Chongqing in Southwest China: From the perspective of PM2.5-bound water uptake property over 2015–2021

Atmospheric Research, Год журнала: 2024, Номер 300, С. 107215 - 107215

Опубликована: Янв. 3, 2024

Язык: Английский

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Study on visibility forecast optimization based on aerosol- meteorological feedbacks in wet conditions

Urban Climate, Год журнала: 2024, Номер 55, С. 101951 - 101951

Опубликована: Май 1, 2024

Язык: Английский

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Chemical-composition characteristics of PM1 and PM2.5 and effects on pH and light-extinction coefficients under different pollution levels in Zhengzhou, China

Journal of Cleaner Production, Год журнала: 2023, Номер 409, С. 137274 - 137274

Опубликована: Апрель 21, 2023

Язык: Английский

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Direct Measurement of Aerosol Liquid Water Content: A Case Study in Summer in Nanjing, China

Toxics, Год журнала: 2024, Номер 12(3), С. 164 - 164

Опубликована: Фев. 20, 2024

Aerosol liquid water content (ALWC) affects the mass loading, optical properties, and toxicity of aerosols. However, measurement ALWC is very rare due to its requirement sophisticated instruments high operational costs. In this work, we improved on our previous simple, low-cost method by using a combination one real-time fine particulate matter (PM2.5) monitor two turbidimeters successfully applied these for direct in PM2.5 Nanjing during summer 2023. The average period occupied ~1/6 total mass, contribution was even greater with elevation concentration. was, as anticipated, closely related relative humidity (RH) concentrations, but it did not always increase air quality index (AQI) fact that polluted periods were often governed O3 levels, levels. also had great impact visibility; could decrease visibility rapidly hazy conditions when dry (~30 μg m−3) or AQI “good” (75~100), indicating classified concentration might actually be “lightly polluted” if included. We found originating from Northeast China lowest yet highest values RH. Moreover, quantification levels can help us understand solubility/bioavailability thus toxic effects some specific components (for example, heavy metals organics). influence classifications should considered assessment health pollution public early warning protection.

Язык: Английский

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Exploring the influence of physical and chemical factors on new particle formation in a polluted megacity

Environmental Science Atmospheres, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

In polluted environments, the condensation sink, along with relative humidity and aerosol liquid water content, plays a key role in suppressing new particle formation events, which appear largely unaffected by chemical composition.

Язык: Английский

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