济南市和青岛市2014—2021年臭氧浓度变化特征及其气象影响因素

为研究济南市和青岛市臭氧(O₃)浓度长期变化特征及其气象影响因素，基于2014—2021年近地面O₃连续8年观测资料和同期气象资料，揭示O₃浓度长期变化特征，分析O₃浓度与气象因子关系，阐明O₃主要输送路径和潜在源区.结果表明：(1)整体上，济南市O₃污染程度高于青岛市，2个城市O₃污染均集中在4—10月.长期趋势上，2014—2021年济南市O₃日最大8 h平均浓度第90百分位数(简称“O₃-8 h 90^th浓度”)总体呈先升后降的趋势，峰值出现在2019年；青岛市2019年和2017年O₃-8 h 90^th浓度相对较高，其他年份O₃-8 h 90^th浓度差异不大.月变化上，济南市O₃-8 h 90^th浓度季节性变化较明显，呈单峰状；而青...

Characteristics of Ozone and Their Relationship with Meteorological Factors from 2014 to 2021 in Jinan and Qingdao,China

Based on surface ozone (O₃) mass concentrations and meteorological data in Jinan and Qingdao from 2014 to 2021, the variation characteristics of daily maximum 8-hour moving average of ozone concentrations (O₃-8 h concentrations) and its relationship with meteorological factors were studied. Backward trajectories were also combined with O₃ concentrations for trajectories clustering and potential source regions of O₃ analysis. The results showed that the O₃ pollution level in Jinan was generally higher than that of Qingdao. The O₃ pollution episodes occurred from April to October. The annual trend of 90th percentile of O₃-8 h concentrations (O₃-8 h 90th concentrations ) in Jinan generally showed an upward trend and then a downward trend from 2014 to 2021. Moreover, the peak value of annual O₃-8 h 90th concentrations in Jinan appeared in 2019. The annual O₃-8 h 90th concentrations of Qingdao in 2019 and 2017 were a little higher than those in other years. The annual O₃-8 h 90th concentrations of Qingdao in the other years showed little difference. The monthly variations of O₃-8 h 90th concentrations in Jinan were more significant, with a unimodal distribution. However, the monthly variations of O₃-8 h 90th concentrations in Qingdao showed a bimodal distribution due to the influence of summer rainy season and clean maritime air mass dilution. The high O₃ concentration was more easily caused by unfavorable weather conditions, such as high temperature, low relative humidity and light wind. Compared with Qingdao, O₃-8 h concentrations in Jinan had a closer correlation with meteorological factors, especially the average air temperature from 08:00 to 17:00 (T_8-17). When T_8-17 was greater than 15 ℃, O₃-8 h concentration in Jinan increased by 6.1 μg/m3 for every 1 ℃ increase in T_8-17. O₃-8 h concentration in Qingdao was fluctuated and increased with the increase of T_8-17. However, for every 1 ℃ increase in T_8-17, O₃-8 h concentration in Qingdao only increased by 1.5 μg/m3. The O₃ concentration in Jinan was much higher, with an average of (113±51) and (109±57)μg/m3, respectively, when the airflow came from southwesterly and south-southeasterly areas, which was the central and eastern junction of Jiangsu-Anhui-Shandong-Henan region. The O₃ concentration in Qingdao was (106±45)μg/m3, together with the southwesterly airflow beginning at the inland regions. The main potential source regions of O₃ in Jinan and Qingdao were in the same region, mainly distribute in the central and eastern of junction Jiangsu-Anhui-Shandong-Henan region and the central Shandong region. Based on all the above research results, the O₃ pollution in Jinan and Qingdao were mainly driven by local emissions. The regions of coordinated inter-regional O₃ prevention and control for Jinan and Qingdao should focus on the central and eastern regions of the junction of Jiangsu-Anhui-Shandong-Henan and the central Shandong.