Comment on gmd-2023-22 DOI Creative Commons
Juan Antonio Añel

Published: June 15, 2023

Abstract. A comprehensive understanding of the effects meteorology, emissions, and chemistry on severe haze is critical in mitigation air pollution. However, such an greatly hindered by nonlinearity atmospheric systems. In this study, we developed quantitative decoupling analysis (QDA) method to quantify chemical reactions, their nonlinear interactions fine particulate matter (PM2.5) pollution running built-in scenario simulations each model step. Different from previous methods, QDA achieves a fully decomposed hourly changes PM2.5 concentration during events into seven parts, including pure meteorological contribution (M), emissions (E), (C), among these processes (i.e., ME, MC, EC, MCE). Via embedding Weather Research Forecasting–Nested Air Quality Prediction Modeling System, employed combined it with Integrated Process Rate study typical heavy episode Beijing. We evaluate performance against in situ quality observations describe analytical factors case. Results showed that M varied most significantly at different stages episode, 0.21 µg⋅m−3⋅h−1 accumulation stage −11.82 removal stage, indicating dominated fluctuation amplitude concentration. acted as important cleaner for non-polluting periods but stopped being effective instead became contributor tended grow rapidly under superimposed influence processes, which would probably mark beginning event. The E ranged 0.63 0.88 owing diurnal variation emissions. was shown increase level haze, becoming largest (0.37 µg⋅m−3⋅h−1) maintenance period, 25 % higher than pre-contamination period. And C+CE made significant stages, reactions are more polluted period other periods. Nonnegligible exist concentrations (−1.83 2.44 – something has generally been ignored studies development heavy-pollution control strategies. helpful eliminating interference obtaining purified result target process have indicative significances. ratio CE C positively correlated speed. For precursors like NH3, smaller value indicated NH3 deficient, thus reducing had efficient controlling effect PM2.5. This highlights can be used realize in-depth adverse conditions judge whether excessive or not. Not only provide researchers policymakers valuable information key behind pollution, also help modelers identify sources uncertainties numerical models.

Language: Английский

Spatiotemporal characteristics of PM2.5 and ozone concentrations in Chinese urban clusters DOI

Chuxiong Deng,

Si Tian,

Zhongwu Li

et al.

Chemosphere, Journal Year: 2022, Volume and Issue: 295, P. 133813 - 133813

Published: Jan. 31, 2022

Language: Английский

Citations

53
Assessment of the effect of meteorological and emission variations on winter PM2.5 over the North China Plain in the three-year action plan against air pollution in 2018–2020 DOI
Huiyun Du, Jie Li, Zifa Wang

et al.

Atmospheric Research, Journal Year: 2022, Volume and Issue: 280, P. 106395 - 106395

Published: Aug. 16, 2022

Language: Английский

Citations

22
Multiple driving factors and hierarchical management of PM2.5: Evidence from Chinese central urban agglomerations using machine learning model and GTWR DOI

Changhong Ou,

Fei Li, Jingdong Zhang

et al.

Urban Climate, Journal Year: 2022, Volume and Issue: 46, P. 101327 - 101327

Published: Nov. 7, 2022

Language: Английский

Citations

18
Evaluating Policy Interventions for Air Quality During a National Sports Event with Machine Learning and Causal Framework DOI Creative Commons
Jing Guo, Ruixin Xu, Bowen Liu

et al.

Atmosphere, Journal Year: 2025, Volume and Issue: 16(5), P. 557 - 557

Published: May 7, 2025

Short-term control measures are often implemented during major events to improve air quality and protect public health. In preparation for the 11th National Traditional Games of Ethnic Minorities China (denoted as “NMG”), held from 8 16 September 2019 in Zhengzhou, China, authorities introduced several pollution measures, including traffic restrictions dust control. study presented herein, we applied automated machine learning-based weather normalisation combined with an augmented synthetic method (ASCM) evaluate effectiveness these interventions. Our results show that impacts NMG were not uniform, varying significantly across pollutants monitoring stations. On average, nitrogen dioxide (NO2) concentrations decreased by 8.6% those coarse particles (PM10) 3.0%. However, interventions had little overall effect on fine (PM2.5), despite clear reductions observed at site, where NO2 PM2.5 levels 7.2 5.2 μg m−3, respectively. These accounted 56.3% policy’s concentration 73.2% its site. Notably, led increase ozone (O3) concentrations. demonstrate moderate short-term intervention, emphasising necessity holistic strategies address pollutant interactions, such oxides (NOX) volatile organic compounds (VOCs), well location-specific variability achieve sustained improvements.

Language: Английский

Citations

0
Spatiotemporal variations and sources of PM2.5 in the Central Plains Urban Agglomeration, China DOI Open Access
Xiaoyong Liu, Chengmei Zhao,

Xinzhi Shen

et al.

Air Quality Atmosphere & Health, Journal Year: 2022, Volume and Issue: 15(9), P. 1507 - 1521

Published: July 6, 2022

Language: Английский

Citations

15
Global PM2.5 and secondary organic aerosols (SOA) levels with sectorial contribution to anthropogenic and biogenic SOA formation DOI

Sahir Azmi,

Mukesh Sharma

Chemosphere, Journal Year: 2023, Volume and Issue: 336, P. 139195 - 139195

Published: June 16, 2023

Language: Английский

Citations

9
Integrated process analysis retrieval of changes in ground-level ozone and fine particulate matter during the COVID-19 outbreak in the coastal city of Kannur, India DOI
Fei Ye, Dipesh Rupakheti, Lin Huang

et al.

Environmental Pollution, Journal Year: 2022, Volume and Issue: 307, P. 119468 - 119468

Published: May 16, 2022

Language: Английский

Citations

14
Impact of Particulate Matter-Centric Clean Air Action Plans on Ozone Concentrations in India DOI

Medhavi Gupta,

Diljit Kumar Nayak,

Sri Harsha Kota

et al.

ACS Earth and Space Chemistry, Journal Year: 2023, Volume and Issue: 7(5), P. 1038 - 1048

Published: May 1, 2023

The grim status of India's air quality is commonly attributed to alarming levels particulate matter (PM). This has led the government formulating several strategies control PM in country. For example, National Clean Air Programme (NCAP) was launched 2019 reduce 30% concentrations by 2024 nonattainment cities (NACs). However, studies across world found these PM-centric action plans be detrimental ozone-related quality. present study among first few investigations that employ Weather Research and Forecasting coupled with Chemistry (WRF-Chem) model comprehensively understand effect NCAP on ozone India. In business-as-usual scenario, while 50% NACs have deteriorating PM2.5 levels, all but 32% other meet Indian Ambient Quality Standards (INAAQS) NCAP. violated INNAQS are mainly situated Indo-Gangetic Plain. ozone, implementation NCAP, 80% INAAQS. reduction indicator ratio formaldehyde oxides nitrogen (HCHO/NOy), indicating region volatile organic compound-limited (VOC-limited), thereby, VOC emissions results a decrease ozone. Further, another reason can increase forest cover as part which increased deposition velocity ∼10.5%. indicates current India, if implemented successfully, also alleviate problem secondary pollutants like saving around 12% lives.

Language: Английский

Citations

8
The Variation in Chemical Composition and Source Apportionment of PM2.5 before, during, and after COVID-19 Restrictions in Zhengzhou, China DOI Creative Commons

Jinting Huang,

Aomeng Cai,

Weisi Wang

et al.

Toxics, Journal Year: 2024, Volume and Issue: 12(1), P. 81 - 81

Published: Jan. 17, 2024

Despite significant improvements in air quality during and after COVID-19 restrictions, haze continued to occur Zhengzhou afterwards. This paper compares ionic compositions sources of PM2.5 before (2019), (2020), (2021) the restrictions explore reasons for haze. The average concentration decreased by 28.5% 2020 27.9% 2021, respectively, from 102.49 μg m-3 2019. secondary inorganic aerosols (SIAs) was 51.87 2019, which 3.1% 12.8% 2021. In contrast, contributions SIAs increased 50.61% (2019) 68.6% (2020) 61.2% (2021). contributed significantly levels 2020-2021. a 22~62% decline NOx 2020-2021, O3 caused similar NO3- (20.69~23.00 m-3) 2020-2021 that (22.93 hindering reduction Zhengzhou. Six sources, including aerosols, industrial emissions, coal combustion, biomass burning, soil dust, traffic were identified positive matrix factorization model 2019-2021. Compared aerosol source 2021 small, contribution 13.32% 12.94% comparison, primary traffic, reduced 29.71% 27.7% results indicated production did not contribute decrease restrictions. Therefore, it is essential understand formation under high low precursor gases mitigate pollution future.

Language: Английский

Citations

2
An unexpected increase in PM2.5 levels in Xi'an during the COVID-19 pandemic restrictions: The interplay of anthropogenic and natural factors DOI

Shuqi Yang,

Xu Yang,

Wang Yu-jing

et al.

Journal of Environmental Sciences, Journal Year: 2024, Volume and Issue: unknown

Published: July 1, 2024

Language: Английский

Citations

2