Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, College of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China.
Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, College of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Zhuhai, 519000, China.
Environ Pollut. 2022 Aug 15;307:119459. doi: 10.1016/j.envpol.2022.119459. Epub 2022 May 11.
Urban and regional ozone (O) pollution is a public health concern and causes damage to ecosystems. Due to the diverse emission sources of O precursors and the complex interactions of air dispersion and chemistry, identifying the contributing sources of O pollution requires integrated analysis to guide emission reduction plans. In this study, the meteorological characteristics leading to O polluted days (in which the maximum daily 8-h average O concentration is higher than the China Class II National O Standard (160 μg/m)) in Guangzhou (GZ, China) were analyzed based on data from 2019. The O formation regimes and source apportionments under various prevailing wind directions were evaluated using a Response Surface Modeling (RSM) approach. The results showed that O polluted days in 2019 could be classified into four types of synoptic patterns (i.e., cyclone, anticyclone, trough, and high pressure approaching to sea) and were strongly correlated with high ambient temperature, low relative humidity, low wind speed, variable prevailing wind directions. Additionally, the cyclone pattern strongly promoted O formation due to its peripheral subsidence. The O formation was nitrogen oxides (NO)-limited under the northerly wind, while volatile organic compounds (VOC)-limited under other prevailing wind directions. Anthropogenic emissions contributed largely to the O formation (54-78%) under the westerly, southwesterly, easterly, southeasterly, or southerly wind, but only moderately (35-47%) under the northerly or northeasterly wind. Furthermore, as for anthropogenic contributions, local emission contributions were the largest (39-60%) regardless of prevailing wind directions, especially the local NO contributions (19-43%); the dominant upwind regional emissions contributed 12-46% (e.g., contributions from Dongguan were 12-20% under the southeasterly wind). The emission control strategies for O polluted days should focus on local emission sources in conjunction with the emission reduction of upwind regional sources.
城市和区域臭氧（O）污染是一个公共卫生问题，同时对生态系统造成损害。由于 O 前体的排放源多样，以及空气扩散和化学过程的复杂相互作用，要确定 O 污染的贡献源，需要进行综合分析以指导减排计划。本研究基于 2019 年的数据，分析了导致广州（GZ，中国）出现 O 污染日（即最大日 8 小时平均 O 浓度高于中国二级 O 标准（160μg/m ）的日子）的气象特征。利用响应面建模（RSM）方法，评估了在不同主导风向条件下 O 的形成机制和源分配。结果表明，2019 年的 O 污染日可分为四类天气模式（即气旋、反气旋、槽和高压接近海），与环境温度高、相对湿度低、风速低、主导风向变化密切相关。此外，气旋模式由于外围下沉而强烈促进了 O 的形成。在北风条件下，O 的形成受氮氧化物（NO）限制，而在其他主导风向条件下，O 的形成受挥发性有机化合物（VOC）限制。在西风、西南风、东风、东南风和南风条件下，人为排放对 O 的形成贡献很大（54-78%），但在北风或东北风条件下，贡献适度（35-47%）。此外，就人为排放而言，无论主导风向如何，本地排放的贡献最大（39-60%），尤其是本地的 NO 贡献（19-43%）；上风方向的主要区域排放贡献 12-46%（例如，在东南风条件下，东莞的贡献为 12-20%）。针对 O 污染日的排放控制策略应侧重于本地排放源，并结合上风区域的减排。
