Meteorological effects on PM2.5 change over a receptor region in regional transport of air pollutants - observational study of recent year emission reduction in central China

Aug 27, 2026

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Anthropogenic emissions and meteorological conditions jointly shape air-pollution changes, yet their relative contributions across receptor regions in regional pollutant transport remain insufficiently quantified. Observational analysis over 2015–2019 for the Twain-Hu Basin (THB) applies the Kolmogorov–Zurbenko filter to separate PM2.5 variations into short-, seasonal-, and long-term components, showing dominance of short-term and seasonal variability while long-term components govern recent trends. Meteorological influences produce a distinct spatial pattern with opposing signals north versus south, linked to upwind diffusion and downward accumulation. Meanwhile, enhanced SO2/NO2 conversion to sulfate/nitrate can offset emission-reduction benefits, indicating amplified roles of gaseous precursors under controlled anthropogenic PM2.5.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages27

Reading Time1 h 8 min

AccessFree to download

Introduction

Background and motivations

Study rationale: emissions vs meteorology

[https://doi.org/10.5194/acp-2021-709](https://doi.org/10.5194/acp-2021-709) Preprint. Discussion started: 30 September 2021 􀀍c Author(s) 2021 . CC BY 4.0 License. Meteorological effects on PM2.5 change over a receptor region in regional transport of air pollutants: observational study of recent year emission reduction in central China Xiaoyun Sun 1, Tianliang Zhao 1, Yongqing Bai2, Shaofei Kong3, Huang Zheng3, Weiyang Hu 1, Xiaodan 5 Ma1, Jie Xiong2 1Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud Precipitation of China Meteorological Administration, PREMIC, Nanjing University of Information Science and Technology, Nanjing, 210044, China 2Institute of Heavy Rain, China Meteorological Administration, Wuhan, 430205, China 10 3Department of Atmospheric Sciences, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, 430074, China Correspondence to: TianLiang Zhao ([tlzhao@nuist.edu.cn](tlzhao@nuist.edu.cn)) Abstract. As an important issue in atmospheric environment, the contributions ofanthropogenic emissions and meteorological 15 conditions to air pollution have been few assessed over the receptor region in regional transport of air pollutants. In this study on observations of environment and meteorology over 2015-2019, the Kolmogorov–Zurbenko (KZ) filter was performed to decompose the PM2.5 variations into multi-time scale components over the Twain-Hu Basin (THB), a receptor region in regional transport of air pollutants in central China, where the short-term, seasonal and long-term components accounted for respectively 47.5%, 41.4% and 3.7% to daily PM2.5 changes. The short-term and seasonal components dominated the day-to- 20 day PM2.5 variations with long-term component determining the change trend of PM2.5 concentrations over recent years. The emission- and meteorology-related long-term PM2.5 components over the THB were identified. The meteorological contribution to PM2.5 declining trend presented the distinct spatial pattern over the THB with northern positive rates up to [https://doi.org/10.5194/acp-2021-709](https://doi.org/10.5194/acp-2021-709) Preprint. Discussion started: 30 September 2021 􀀍c Author(s) 2021 . CC BY 4.0 License. 25 30 35 40 45 61.92% and southern negative rates down to-24.93%. The opposite effects of meteorology on PM2.5 pollution could accelerate and offset the effects of emission reductions in the northern and southern THB, which is attributed to the upwind diffusion and downward accumulation of air pollutants over the receptor region in regional PM2.5 transport. It is noteworthy that the increasing conversion efficiencies of SO2 and NO2 to sulfate and nitrate for secondary PM2.5 could offset the effects of PM2.5 emission reduction on air pollution in the THB during recent years, revealing the enhancing contribution of gaseous precursor emissions to PM2.5 concentrations with controlling anthropogenic emissions of PM2.5 and the gaseous precursors over the receptor region in regional transport of air pollutants. 1. Introduction Haze pollution with high levels of PM2.5 (fine particulate matters with aerodynamic diameters equal to or less than 2.5 µm) has been a serious problem in atmospheric environment (Peng et al., 2016; Wang et al., 2016) with adverse influences on air quality and human health (Cao et al., 2012; Crouse et al., 2012) . In recent years, the large areas over Central and Eastern China (CEC) have undergone haze pollution with unprecedentedly high PM2.5 levels in the regions covering North China Plain (NCP), Yangtze River Delta (YRD), Pearl River Delta (PRD) and Sichuan Basin (SB) (Zhang et al., 2012; Lin et al., 2018; Guo et al., 2017). In order to improve air quality with reducing air pollutant emissions, Chinese government has implemented an Action Plan of controlling anthropogenic emissions since September

FAQs

What method is used to analyze PM2.5 variations over the receptor region?

The study applies the Kolmogorov–Zurbenko (KZ) filter to decompose PM2.5 changes into multiple time-scale components.

Which time-scale components dominate daily PM2.5 variations in the Twain-Hu Basin?

Short-term and seasonal components dominate the day-to-day PM2.5 variations, while the long-term component mainly determines the concentration trend over recent years.

How do meteorological effects differ across the Twain-Hu Basin spatially?

Meteorological contributions show a distinct pattern: positive rates in the northern THB and negative rates in the southern THB, attributed to upwind diffusion and downward accumulation of pollutants.

Aug 27, 2026

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