Surface Ozone in the Yangtze River Delta, China: A Synthesis of Basic Features, Meteorological Driving Factors, and Health Impacts

Abstract

Ozone (O 3) is of great importance to air quality in the Yangtze River Delta (YRD) region, China. Focusing on surface O 3 in the YRD, its spatiotemporal characteristics, meteorological driving factors, and health impacts are investigated based on surface O 3 observations in this study. We find that from 2015 to 2019, most cities failed to meet the national standards and O 3 pollution mainly occurred in warm seasons (April-September). Surface O 3 in the YRD increased in the recent years, so did tropospheric column O 3. Spatially, surface shows a significant positive autocorrelation over the YRD except for 2019, and high O 3 values mainly gather in the central of the YRD. The first two empirical orthogonal functions (EOFs) of O 3 accounted for 37.4% and 20.0% of the total variance in O 3 , respectively, with their spatial patterns characterized by the same phase and west and east contrast, respectively. The EOF1 is related to the change in radiation and the EOF2 is attributed to regional transport by prevailing westerly wind. Downward UV radiation, temperature and u wind are crucial factors. The premature mortality caused by O 3 for respiratory disease in the YRD is estimated to be 5,889 cases per year. Furthermore, we find that premature mortality is more sensitive to O 3 concentration than population, suggesting that controlling peak O 3 concentration can bring great health benefits. ZHAN ET AL.

Land-surface forcing and anthropogenic heat modulate ozone by meteorology: A perspective from the Yangtze River Delta region

“…Under adverse weather conditions, O3 pollution episodes occur frequently in the YRD Zhan et al, 2021). Sometimes, O3 pollution can spread throughout the YRD and cause regional O3 pollution, affecting an area of up to 3.5 million square kilometers and harming more than 200 million people.…”

“…With dense population and huge energy consumption, this area is now suffering from air quality deterioration (Ding et al, 2013;Xie et al, 2017), especially severe O3 pollution in recent years (Zhan et al, 2020(Zhan et al, , 2021. It was reported that 16 out of the 26 typical cities in the YRD failed to meet the urban national standard for O3 in 2017 (Bulletin on the state of China's ecological environment in 2018, http://www.cleanairchina.org/ product/9943.html), and to make matters worse, O3 concentration has been rising in this region during the past few years (Li et al, 2020;.…”

Spatiotemporal Variability of Air Stagnation and its Relation to Summertime Ozone in the Yangtze River Delta of China

“…The hourly values for each city are calculated by averaging the concentrations at all national monitoring sites in that city. Identification and handling of invalid and lacking data are also manually performed during data processing, following the methods adopted in some previous studies (Xie et al, 2016b;Shu et al, 2016;Gao et al, 2020Gao et al, , 2021Zhan et al, 2020Zhan et al, , 2021. The YRD region consists of 26 typical cities.…”

“…O 3 pollution is the typical atmospheric environment problem in this region, with a positive trend in O 3 concentration in recent years (Li et al, 2011;Ding et al, 2016;Xu et al, 2018). In previous studies, it was found that high O 3 events generally occur in hot and dry seasons, and are usually related to strong photochemical reactions and high air temperature (Chan and Yao, 2008;Li et al, 2011;Ma et al, 2012;Ding et al, 2013Ding et al, , 2016Xie et al, 2016b;Hu et al, 2016;Pu et al, 2017;Gao et al, 2021;Zhan et al, 2021). The subtropical high also have significant impacts on O 3 concentrations (Shu et al, 2016;Gao et al, 2020;Zhan et al, 2020).…”

“…In and around the megacities, poor air quality is usually caused by high emissions and adverse meteorological conditions characterized by light wind and less precipitation (Chan and Yao, 2008;Ma et al, 2012;Li et al, 2017;Xie et al, 2017;Xu et al, 2018;Shen et al, 2021;Wang et al, 2021). In recent years, under the very strict emission control strategies implemented by the Chinese government, the effects of meteorological conditions on air pollution have attracted more attention and interest from researchers, especially in the Beijing-Tianjin-Hebei (BTH) region (Xu et al, 2011;Zhang et al, 2016), the Yangtze River Delta (YRD) region (Shu et al, 2016(Shu et al, , 2017Xie et al, 2016aXie et al, , 2016bGao et al, 2020Gao et al, , 2021Zhan et al, 2020Zhan et al, , 2021, the Pearl River Delta (PRD) region (Xie et al, 2016c;Zhu et al, 2017) and the Sichuan Basin (Zhan et al, 2019;Yang et al, 2020Yang et al, , 2021. Previous investigations have found that air quality can be worse under stagnant weather conditions.…”