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

Environmental Research Letters, Год журнала: 2022, Номер 17(12), С. 123001 - 123001

Опубликована: Ноя. 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.

Язык: 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, Год журнала: 2020, Номер 48(2)

Опубликована: Дек. 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.

Язык: Английский

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Multi-pollutant air pollution and associated health risks in China from 2014 to 2020

Atmospheric Environment, Год журнала: 2021, Номер 268, С. 118829 - 118829

Опубликована: Ноя. 5, 2021

Язык: Английский

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Impacts of aerosol–photolysis interaction and aerosol–radiation feedback on surface-layer ozone in North China during multi-pollutant air pollution episodes

Atmospheric chemistry and physics, Год журнала: 2022, Номер 22(6), С. 4101 - 4116

Опубликована: Март 29, 2022

Abstract. We examined the impacts of aerosol–radiation interactions, including effects aerosol–photolysis interaction (API) and feedback (ARF), on surface-layer ozone (O3) concentrations during four multi-pollutant air pollution episodes characterized by high O3 PM2.5 levels 28 July to 3 August 2014 (Episode1), 8–13 2015 (Episode2), 5–11 June 2016 (Episode3), 2017 (Episode4) in North China, using Weather Research Forecasting with Chemistry (WRF-Chem) model embedded an integrated process analysis scheme. Our results show that API ARF reduced daytime shortwave radiative fluxes at surface 92.4–102.9 W m−2 increased atmosphere 72.8–85.2 m−2, as values were averaged over complex areas (CAPAs) each episodes. As a result, stabilized decreased planetary boundary layer height 10 m wind speed 129.0–249.0 0.05–0.15 s−1, respectively, CAPAs Aerosols simulated reduce near-surface photolysis rates J[NO2] J[O1D] 1.8 × 10−3–2.0 10−3 5.7 10−6–6.4 10−6 All same conclusion, which is reduction larger than ARF. (ARF) was change −8.5 ppb (parts per billion; −2.9 ppb), −10.3 (−1.0 −9.1 (−0.9 −11.4 (+0.7 ppb) episodes, respectively. Process indicated weakened chemical production made greatest contribution effect, while vertical mixing key for effect. conclusions suggest future reductions may lead increases due should be considered quality planning.

Язык: Английский

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Observational Evidence of Aerosol Radiation Modifying Photochemical Ozone Profiles in the Lower Troposphere

Geophysical Research Letters, Год журнала: 2022, Номер 49(15)

Опубликована: Июль 21, 2022

Abstract Aerosol optical effects can trigger complex changes in solar shortwave radiation (SW) the atmosphere, resulting significant impacts on photochemistry and vertical structure of ozone. This paper provides observational evidence aerosol absorbing scattering modifying SW ozone profiles low troposphere. Using field measurements observation‐based model simulations, we demonstrated that aerosols decreased SW, substantial inhibition production throughout boundary layer (BL). A similar effect occurred within lower BL under sufficient aerosols. However, augmentation played an additional role enhancing photolysis rate promoting generation upper BL. Hence, as well our simulations disentangled radiative different types structures

Язык: Английский

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Stratospheric influences on surface ozone increase during the COVID-19 lockdown over northern China

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

Опубликована: Июнь 29, 2023

Abstract Surface ozone increased unexpectedly over northern China during the COVID-19 lockdown (CLD) period (23 January–29 February 2020), which was characterized by vigorous emission reduction. The reasons for this enhancement have been speculated from perspectives of chemical responses to emissions and meteorology. As known, processes natural stratospheric injecting troposphere are most active in winter spring. Yet, little attention paid influences on enhancement. Here we report a intrusion (SI) that reached surface 15–17 CLD. coevolution enhanced sharply declined carbon monoxide relative humidity (RH) indicative SI occurrence. We show facilitated cutoff low system led abnormally high part China. estimate period, injected constituted up 40–45% If inputs were scaled entire CLD these would account 4–8% ozone. In view unexpected increase CLD, event could explain 18% some cities, average 5–10% larger areas affected. Hence, nonnegligible urge extra consideration sources disentangling role reduction meteorological conditions elsewhere world.

Язык: Английский

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Weakened aerosol–radiation interaction exacerbating ozone pollution in eastern China since China's clean air actions

Atmospheric chemistry and physics, Год журнала: 2024, Номер 24(7), С. 4001 - 4015

Опубликована: Апрель 3, 2024

Abstract. Since China's clean air action, PM2.5 (particulate matter with an aerodynamic equivalent diameter of 2.5 µm or less) quality has improved, while ozone (O3) pollution become more severe. Here we apply a coupled meteorology–chemistry model (WRF-Chem: Weather Research and Forecasting to Chemistry v3.7.1) quantify the responses aerosol–radiation interaction (ARI) anthropogenic emission reductions from 2013 2017, including aerosol–photolysis (API) related photolysis rate change feedback (ARF) meteorological field their contributions O3 increases over eastern China in summer winter. Sensitivity experiments show that decreased emissions play prominent role increased daily maximum 8 h average (MDA8) both (+1.96 ppb vs. +0.07 ppb) winter (+3.56 −1.08 than impacts changed conditions urban areas. The caused by can result weaker impact ARI on concentrations, which superimposes its effect worsened quality. weakened due aggravates (winter) +0.81 (+0.63 ppb), averaged China, API contributing 55.6 % (61.9 %) ARF 44.4 (38.1 %), respectively. This superimposed is significant for areas during (+1.77 ppb). Process analysis indicates enhanced chemical production dominant process concentrations study innovatively reveals adverse quality, indicating stringent coordinated control strategies should be implemented improvements future

Язык: Английский

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Impact of aerosol-radiation interaction and heterogeneous chemistry on the winter decreasing PM2.5 and increasing O3 in Eastern China 2014–2020

Journal of Environmental Sciences, Год журнала: 2024, Номер 151, С. 469 - 483

Опубликована: Апрель 18, 2024

Язык: Английский

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Summertime ozone pollution in China affected by stratospheric quasi-biennial oscillation

Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(2), С. 1533 - 1544

Опубликована: Янв. 26, 2023

Abstract. In recent years, the near-surface ozone (O3) level has been rising fast in China, with increasing damage to human health and ecosystems. this study, impact of stratospheric quasi-biennial oscillation (QBO) on interannual variations summertime tropospheric O3 over China is investigated based GEOS-Chem model simulations satellite retrievals. QBO a significant positive correlation concentrations central (92.5–112.5∘ E, 26–38∘ N) when sea surface temperature (SST) eastern tropical Pacific warmer than normal, coefficient 0.53, but no effect under cold SST anomaly. Compared easterly phase QBO, have an increase up 3 ppb (5 % relative average) during its westerly warm also increases above upper troposphere, maximum 2–3 (3 %–5 %) 850–500 hPa comparing phase. Process-based analysis sensitivity suggest that mainly attributed anomalous downward transport anomaly occurs Pacific, while local chemical reactions horizontal processes partly offset increase. This work suggests potentially important role related vertical process affecting air quality, indication for pollution prediction prevention.

Язык: Английский

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Detecting causal relationships between fine particles and ozone based on observations in four typical cities of China

Environmental Research Letters, Год журнала: 2024, Номер 19(5), С. 054006 - 054006

Опубликована: Март 25, 2024

Abstract As the concentration of fine particles (PM 2.5 ) is declining, ozone (O 3 has been increasing in China recent years. To collaboratively control PM and O , it critical to understand relationship between two identify major controlling factors. We use a convergent cross-mapping method detect causal daily maximum 8 h average (MDA8) concentrations Beijing, Taizhou, Shenzhen Chengdu, China, four seasons 2015–2021. In addition, we also examined effects atmospheric oxidation capacity, precursors meteorological elements on MDA8 cities. are strongly positively correlated show bidirectional relationships during Beijing Taizhou summer Shenzhen, due mainly strong photochemical reactions daytime. During winter, relationships, but significantly negatively correlated, driven by NO 2 relative humidity. Weak bidirectional, unidirectional no detected other these cities, top three factors differ from those . Season-, city- pollutant-specific measures required.

Язык: Английский

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