A comprehensive study on ozone pollution in a megacity in North China Plain during summertime: Observations, source attributions and ozone sensitivity

Environment International, Journal Year: 2020, Volume and Issue: 146, P. 106279 - 106279

Published: Dec. 1, 2020

Tropospheric ozone (O3) pollution has been becoming prominent in North China Plain (NCP) since last decade. In order to clarify the source contribution and formation mechanism of O3, critical precursors volatile organic compounds (VOCs) were measured with both on-line off-line methods Luoyang City summer 2019. The concentrations nitrogen oxides (NOx, sum NO NO2) O3 simultaneously monitored. Fifty-seven VOCs U.S. Photochemical Assessment Monitoring Station (PAMS) showed daily a range 14.5 ± 5.33 29.2 11.2 ppbv Luoyang, which comparable those other Chinese megacities. mass compositions determined, comparatively low proportions alkanes (<50%) but high fractions photoreactive alkenes alkyne. Source apportionment was conducted by Hybrid Environmental Receptor Model (HERM). results indicated that industrial (38.5%) traffic (32.0%) two dominated sources urban, while biogenic residential had contributions 15.8% 13.8%, respectively. To further measure sensitivity its attribution, WRF-CHEM model adopted this study. variation between observation stimulation using local emission inventory an index agreement (IOA) 0.85. simulation average 43.5% associated regional transportation, revealing importance inter-regional prevention control policy. Traffic emissions major episode occurred from July 21 27, 2019 (when concentration over 150 μg m−3) 22.9% 18.3%, isopleths proved atmosphere transitional regime collectively controlled NOx. This different observations main cities NCP before implantations strict controls. additionally designated would move forward or shift NOx after reduction 45% during episode. Similar patterns also reported megacities such as Beijing Shanghai, due tightening policies. Our do support simultaneous controls effective reductions tropospheric Luoyang. Meanwhile, joint policies on can potentially overwhelm current pollutions China.

Language: Английский

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Impact of meteorological condition changes on air quality and particulate chemical composition during the COVID-19 lockdown

Journal of Environmental Sciences, Journal Year: 2021, Volume and Issue: 109, P. 45 - 56

Published: Feb. 26, 2021

Language: Английский

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Ambient fine particulate matter and ozone pollution in China: synergy in anthropogenic emissions and atmospheric processes

Environmental Research Letters, Journal Year: 2022, Volume and Issue: 17(12), P. 123001 - 123001

Published: Nov. 9, 2022

Abstract Since 2013, China has taken a series of actions to relieve serious PM 2.5 pollution. As result, the annual concentration decreased by more than 50% from 2013 2021. However, ozone pollution become pronounced, especially in North Plain. Here, we review impacts anthropogenic emissions, meteorology, and atmospheric processes on ambient loading components O 3 China. The reported influence interannual meteorological changes during 2013–2019 ranged 10%–20% 20%–40%, respectively. During same period, emissions NO x , SO 2 primary NMVOC NH are estimated decrease 38%, 51%, 35%, 11% 17%, Such emission reduction is main cause for across imbalanced reductions various precursors also result variation nitrate gas-particle partitioning hence an increase fraction . enhancement oxidation capacity can have substantial impact secondary which partly explained growth organic aerosols haze events COVID-19 shutdown period. uneven suggested be most important reason rapid after 2013. In addition, may affected formation via radiation effects heterogeneous reactions. Moreover, climate change expected both processes. extent pathways -O interplay how it will impacted changing conditions making synergetic control difficult. Further research interaction needed provide basis scientifically-grounded effective co-control strategy.

Language: Английский

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Marked Impacts of Pollution Mitigation on Crop Yields in China

Earth s Future, Journal Year: 2022, Volume and Issue: 10(11)

Published: Oct. 27, 2022

Abstract Plant growth and crop harvest are impacted by both climate change air pollution. However, their relative importance in yields remains elusive, especially heavily polluted regions. Here we develop yield prediction models, based on a large volume of historical data, as well pollution records China since 1980. A long‐term surface ozone concentration data set is developed from machine‐learning model various observations. An assessment four factors reveals the critical role particulate regulating interannual variations China. During 2010–2018, find that mitigation outweighs negative impacts concurrent change, resulting 0.5%–1.9% net increases nationwide, despite North Plain. Looking to future, particularly temperature increase, will dominate over profoundly reduce future maize rice 0.6 2.8% 10 yr −1 2050. Our findings call for attention threat global food security absence persistence warming.

Language: Английский

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Characteristics of aerosol chemistry and acidity in Shanghai after PM2.5 satisfied national guideline: Insight into future emission control

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 827, P. 154319 - 154319

Published: March 4, 2022

Language: Английский

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Effects of significant emission changes on PM2.5 chemical composition and optical properties from 2019 to 2021 in a typical industrial city of eastern China

Atmospheric Research, Journal Year: 2024, Volume and Issue: 301, P. 107287 - 107287

Published: Feb. 8, 2024

Language: Английский

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Enhanced PM_2.5 Decreases and O₃ Increases in China During COVID‐19 Lockdown by Aerosol‐Radiation Feedback

Geophysical Research Letters, Journal Year: 2020, Volume and Issue: 48(2)

Published: Dec. 7, 2020

Abstract We apply an online‐coupled meteorology‐chemistry model (WRF‐Chem) embedded with improved process analysis to examine aerosol‐radiation feedback (ARF) impacts on effectiveness of emission control due Coronavirus Disease 2019 (COVID‐19) lockdown over North China Plain. Emission reduction alone induces PM 2.5 decrease by 16.3 μg m −3 and O 3 increase 10.2 ppbv during COVID‐19 lockdown. The ARF enhances 2.7 (16.6%) 0.8 (7.8%). ARF‐induced enhancement decline is mostly attributed aerosol chemistry process, while rise ascribed physical advection vertical mixing processes. A set sensitivity experiments reductions in different degrees indicate that the enhancements declines (O rises) follow a robust linear relationship emission‐reduction‐induced decreases. fitted has important implication for assessing abatement at any extent.

Language: Английский

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Changes in Air Quality from the COVID to the Post-COVID Era in the Beijing-Tianjin-Tangshan Region in China

Aerosol and Air Quality Research, Journal Year: 2021, Volume and Issue: 21(12), P. 210270 - 210270

Published: Jan. 1, 2021

This article discussed air quality changes in the Beijing-Tianjin-Tangshan (BTT) region. The index (AQI) values, and concentrations of PM2.5, PM10, SO2, CO, NO2, O3 BTT region during COVID-19 outbreak 2020 were, respectively, 79.4, 47.2 μg m-3, 73.4 10.3 0.87 mg 33.6 90.7 m-3. However, they 102.7, 61.4 121.0 9.0 0.88 40.1 84.0 m-3 same period 2021, which is an increase 29.2%, 30.1%, 64.8%, -12.9%, 1.94 %, 19.5%, -7.4% compared with values 2020. combined proportions grade I II were 16.7% higher than those so has deteriorated rapidly from to post-COVID era 2021. possible reasons for poorer are that frequency dusty weather pollutant discharge increased, meteorological conditions have been relatively unfavorable. average AQI 2021 respectively decreased by 14.8%, 29.0%, 14.6%, 22.5%, 37.4%, 8.7%, It also worth noting all pollution consistent. 18.4% 2020, indicates obviously improved a series clean policies actions, as well favorable atmospheric diffusion conditions. These results indicate play very important role improving quality.

Language: Английский

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Vertical Distributions of Primary and Secondary Aerosols in Urban Boundary Layer: Insights into Sources, Chemistry, and Interaction with Meteorology

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(8), P. 4542 - 4552

Published: March 26, 2021

Vertical measurements are essential for the characterization of aerosol and boundary layer interactions; yet, our knowledge vertical profiles primary secondary species in megacities is limited. Here, we conducted comprehensive particle composition on a 325 m meteorological tower with two chemical speciation monitors winter urban Beijing. The simultaneous at ground level, 140, 240 illustrated similar bulk these three heights. However, ratios varied significantly among different species. Particularly, aqueous phase photochemical-related organic (SOA) (aqOOA/OOA) decreased significantly, accompanied by increases to OA, highlighting properties OA between level aloft, large impacts changes meteorology gaseous precursors SOA formation. NO3/SO4 ratios, however, were mostly insignificant, likely due low relative humidity water content that inhibited nocturnal heterogeneous reactions residual layer. Considerable early morning also observed most species, demonstrating impact air pollution 2nd day.

Language: Английский

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Comparison of Phase States of PM_2.5 over Megacities, Seoul and Beijing, and Their Implications on Particle Size Distribution

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(24), P. 17581 - 17590

Published: Dec. 2, 2022

Although the particle phase state is an important property, there scant information on it, especially, for real-world aerosols. To explore of fine mode aerosols (PM2.5) in two megacities, Seoul and Beijing, we collected PM2.5 filter samples daily from Dec 2020 to Jan 2021. Using optical microscopy combined with poke-and-flow technique, states bulk as a function relative humidity (RH) were determined compared ambient RH ranges cities. was found be liquid semisolid but mostly solid Beijing. The dominant polluted days, while clean days Seoul. These findings can explained by aerosol water content related chemical compositions at RH; much higher than Furthermore, overall observed Beijing interrelated size distribution. results this study aid better understanding fundamental physical properties examining how these are linked urban atmospheres.

Language: Английский

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