Li Bo-Wen, Zhang Kai, Gao Jian, Gao Qing-Xian, Luo Yu-Qian, Li Ying-Xin, Ren Jia-Hao, Cha Zhi-Chun
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Huan Jing Ke Xue. 2024 Aug 8;45(8):4375-4384. doi: 10.13227/j.hjkx.202306068.
PM pollution remains prominent in autumn, whereas O pollution gradually manifests in summer. To understand the dual high characteristics and meteorological effects of PM and O in the summer and early autumn of 2021 in the Beijing-Tianjin-Hebei and surrounding areas, the spatiotemporal distribution characteristics of PM and O concentrations, as well as meteorological conditions, subtropical high index, and weather situation in the Beijing-Tianjin-Hebei and surrounding areas were analyzed. The results showed that PM concentration and DPO （O daily maximum 8h mean minus O concentration at 06：00） from June to September 2021 decreased compared with those in the same period in 2020 and 2022, and high concentrations were mainly occurring in June. The overall PM concentration and DPO showed a gradual decrease from the middle to the north and south, with synchronous spatiotemporal changes. The hourly value of PM concentration presented a multimodal distribution, reaching the peak at 07：00-10：00 and 22：00-24：00. O concentration showed an opposite trend of change with PM concentration, reaching their peak from 14：00-16：00. When DPO and the concentration of PM were high, the characteristics of near-surface meteorological elements were characterized by temperatures ranging from 24.0-28.0℃, relative humidity concentrated at 58.4%-76.3%, and wind speeds ranging from 1.5-3 m·s. There was a high lag correlation between the subtropical high index and DPO. When the subtropical high was farther and stronger from the Beijing-Tianjin-Hebei and surrounding areas, DPO was higher. The major weather patterns with both high PM and O concentrations in the study area were near surface low-pressure front, high-pressure type, and frontal type. The high altitude was controlled by high-pressure ridges, and the subtropical high ridge line was stable between 21°-28°N.
秋季细颗粒物（PM）污染依然突出，而臭氧（O）污染在夏季逐渐显现。为了解2021年京津冀及周边地区夏末秋初PM和O的双重高值特征及气象效应，分析了京津冀及周边地区PM和O浓度的时空分布特征，以及气象条件、副热带高压指数和天气形势。结果表明，2021年6月至9月的PM浓度和臭氧日最大8小时滑动平均浓度与06：00的臭氧浓度差值（DPO）较2020年和2022年同期有所下降，高浓度主要出现在6月。PM浓度和DPO总体上呈现出由中部向南北逐渐降低的趋势，时空变化同步。PM浓度小时值呈多峰分布，在07：00 - 10：00和22：00 - 24：00达到峰值。O浓度与PM浓度呈现相反的变化趋势，在14：00 - 16：00达到峰值。当DPO和PM浓度较高时，近地面气象要素特征为气温24.0 - 28.0℃，相对湿度集中在58.4% - 76.3%，风速1.5 - 3米/秒。副热带高压指数与DPO之间存在较高的滞后相关性。当副热带高压离京津冀及周边地区更远、更强时，DPO更高。研究区域内PM和O浓度均较高的主要天气型为近地面低压锋、高压型和锋面型。高空受高压脊控制，副热带高压脊线稳定在21° - 28°N之间。
