School of Surveying and Geo-Informatics, Shandong Jianzhu University, Jinan, 250101, China.
State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China.
J Environ Manage. 2021 Jun 15;288:112368. doi: 10.1016/j.jenvman.2021.112368. Epub 2021 Mar 24.
A better knowledge of surface ozone variations and the relevant influential factors is of great significance for controlling frequent ozone pollution events. In this study, we first examined the primary variation patterns of surface ozone in space and time across China via a clustering analysis on the basis of daily maximum 8h average surface ozone (MDA8) between 2015 and 2018. Statistical models were then established between MDA8 and a set of influential factors to pinpoint dominant factors contributing to regional MDA8 variations. The clustering results revealed four typical variation patterns of MDA8 in China given distinct pollution levels, seasonality, and long-term trends. Statistical modeling results indicated that the seasonal variability of MDA8 was closely associated with UV radiation and meteorological factors like boundary layer height, temperature and relative humidity. In contrast, the long-term trends of MDA8 were largely linked to ozone precursors and meteorological variables including temperature, relative humidity, and total cloud cover. Moreover, the phenomenal increasing trends of MDA8 in North China were found to be statistically associated with the depletion of nitrogen dioxide (NO) and carbon monoxide (CO). Specifically, substantial increases in volatile organic compounds (VOCs) along with depletions in NO and CO significantly boosted the photochemical ozone formation chain process in a VOC-limited regime like the North China plain. Overall, the inferred linkage in this study provides evidence and clues to help control increasing ozone pollution events in North China.
更好地了解地表臭氧变化及其相关影响因素对于控制频繁的臭氧污染事件具有重要意义。在本研究中，我们首先通过对 2015 年至 2018 年期间每日最大 8 小时平均地面臭氧（MDA8）的聚类分析，检验了中国地表臭氧的主要时空变化模式。然后，我们建立了 MDA8 与一组影响因素之间的统计模型，以确定导致区域 MDA8 变化的主要因素。聚类结果揭示了中国 MDA8 的四种典型变化模式，具有不同的污染水平、季节性和长期趋势。统计模型结果表明，MDA8 的季节性变化与紫外线辐射以及边界层高度、温度和相对湿度等气象因素密切相关。相比之下，MDA8 的长期趋势主要与臭氧前体物以及包括温度、相对湿度和总云量在内的气象变量有关。此外，华北地区 MDA8 的显著增加趋势在统计学上与二氧化氮（NO）和一氧化碳（CO）的消耗有关。具体而言，随着挥发性有机化合物（VOCs）的大量增加以及 NO 和 CO 的消耗，在像华北平原这样的 VOC 受限地区，光化学反应臭氧形成链过程显著增强。总的来说，本研究中推断出的联系为控制华北地区日益增加的臭氧污染事件提供了证据和线索。
