Assessment of meteorology vs. control measures in the China fine particular matter trend from 2013 to 2019 by an environmental meteorology index

• Main Authors: S. Gong, H. Liu, B. Zhang, J. He, H. Zhang, Y. Wang, S. Wang, L. Zhang, J. Wang
• Format: Article
• Language: English
• Published: Copernicus Publications 2021-03-01
• Series: Atmospheric Chemistry and Physics
• Online Access: https://acp.copernicus.org/articles/21/2999/2021/acp-21-2999-2021.pdf

<p>A framework was developed to quantitatively assess the contribution of meteorology variations to the trend of fine particular matter (PM<span class="inline-formula">_2.5</span>) concentrations and to separate the impacts of meteorology from the control measures in the trend, based upon the Environmental Meteorology Index (EMI). The model-based EMI realistically reflects the role of meteorology in the trend of PM<span class="inline-formula">_2.5</span> and is explicitly attributed to three major factors: deposition, vertical accumulation and horizontal transports. Based on the 2013–2019 PM<span class="inline-formula">_2.5</span> observation data and re-analysis meteorological data in China, the contributions of meteorology and control measures in nine regions of China were assessed separately by the EMI-based framework. Monitoring network observations show that the PM<span class="inline-formula">_2.5</span> concentrations have declined by about 50 % on the national average and by about 35 % to 53 % for various regions. It is found that the nationwide emission control measures were the dominant factor in the declining trend of China PM<span class="inline-formula">_2.5</span> concentrations, contributing about 47 % of the PM<span class="inline-formula">_2.5</span> decrease from 2013 to 2019 on the national average and 32 % to 52 % for various regions. The meteorology has a variable and sometimes critical contribution to the year-by-year variations of PM<span class="inline-formula">_2.5</span> concentrations, 5 % on the annual average and 10 %–20 % for the fall–winter heavy pollution seasons.</p>