华北平原和山区城市PM2.5和O3变化关系比较分析

利用2015~2019年环境监测数据，对比分析华北地区平原城市保定市和山区城市张家口市PM_2.5和O₃变化和相关关系.结果表明：保定市PM_2.5夏低冬高，O₃夏高冬低，日变化为午后单峰型，而张家口市PM_2.5浓度低，日变化幅度较弱，冬季O₃日变化为午后峰值和凌晨5：00左右弱峰值双峰型.张家口市冬季全天及春夏秋季夜间O₃浓度显著高于保定市，甚至夏季出现夜间O₃超标异常，最高浓度达到202μg/m³，反映了平原城市和清洁山区大气物理化学过程变化的影响.PM_2.5和O₃在4~9月为正相关，11~3月为负相关；保定市PM_2.5-O₃相关系数日变化呈单峰型，张家口市为双峰型变化，凌晨和午后各有一峰值，华北地区平原污染区和高山相对清洁区，大气复合污染物PM_2.5和O₃作用关系的日变化及季节特征具有明显差异.

Comparative analysis of the relationship between PM2.5 and O3 in plain and mountainous cities in North China

By using the environmental monitoring data from 2015 to 2019, This study presented a comparative analysis of PM_2.5 and O₃ changes and their relationships between the plain city Baoding (BD)and the mountainous city Zhangjiakou (ZJK) in North China. In BD, PM_2.5 concentrations were low in summer and high in winter, O₃ was high in summer and low in winter with a diurnal single-peak in afternoon, while in ZJK, the low PM_2.5 concentrations oscillated diurnally with a weaker amplitude. And the wintertime O₃ presented the bimodal peak in the afternoon and around 5:00 in the morning. The O₃ concentrations in ZJK in winter and during nighttime in spring, summer and autumn were significantly higher than those in BD. Even in summer, nighttime O₃ exceeded the air pollution standard, with the highest concentration reaching up to 202μg/m³, reflecting the distinct influence of changes in atmospheric physical and chemical processes in plain cities and clean mountains. PM_2.5 and O₃ were positively and negatively correlated respectively from April to September and from November to following March; the daily change of the correlation coefficient of PM_2.5-O₃ in BD is unimodal, and bimodal, each in the early morning and afternoon in ZJK The obvious differences were found in the diurnal and seasonal variations of the relationship between atmospheric compound pollutants PM_2.5 and O₃ in the plain polluted area and the relative clean mountainous area in North China.