潮州市城区PM2.5-O3复合污染特征及其发生的天气型分析

Characteristics and Synoptic Patterns of PM2.5-O3 Complex Pollution in Chaozhou City

关键词:  潮州  PM2.5-O3  复合污染  天气型  气象因子

Key words:  Chaozhou  PM2.5-O3  complex pollution  synoptic patterns  meteorological factors

摘要:

利用广东省潮州市区 2014—2020 年空气质量逐小时浓度数据，分析了 PM2.5、O3浓度及复合污染的年、月、日变化特征，利用再分析资料对天气形势进行分型，结合相应时段潮州国家气象观测站资料，分析 PM2.5-O3与天气型及气象因子的关系。结果表明：2014—2020 年潮州市区年平均 ρ(PM2.5)、ρ(O3-8 h)及复合污染出现日数均呈波动下降趋势，月平均 ρ(PM2.5)最高出现在 3月，月平均 ρ(O3-8 h)最高出现在 10月，两种污染物最低均出现在 6月。复合污染出现较多的是 10月—次年 4月。PM2.5、O3污染具有一定相互作用，当其中一种污染物日均浓度较高时另一种污染物的浓度相应较高，同时污染物浓度的日较差也会相应增大；污染物峰谷值出现时间表现为空气污染较严重时，O3峰值出现时间在 15 时，PM2.5峰值出现在 19—20 时。造成潮州复合污染的天气型主要为变性高压脊(DR)、反气旋(AC)、副高+变性高压脊(SD)、均压场(UP)天气型，主要出现在秋、冬、春季，少数出现在初夏。4种天气型出现的季节不同，但总体来说晴朗干燥是出现复合污染的主要气象因素。

Abstract:

Based on the Chaozhou urban area's hourly air quality concentration data from 2014 to 2020, the annual, monthly and daily variation characteristics of PM2.5-O3 complex pollution were analyzed. The reanalysis data were used to classify the weather situation, and combined with the meteorological data from Chaozhou National Station in the corresponding period, the relationship between PM2.5-O3 and synoptic patterns and meteorological factors was analyzed in this paper. The results showed that the annual mean ρ(PM2.5), ρ(O3-8 h) and the number of days of complex pollution in the Chaozhou urban area showed a decreasing trend during 2014—2020. The highest monthly mean ρ(PM2.5) appeared in March, the highest monthly mean ρ(O3-8 h) appeared in October, and the lowest of both pollutants appeared in June. The most complex pollution occurred from October to April of the following year. PM2.5 and O3 pollution had certain interactions. When the daily average concentration of one pollutant was higher, the concentration of the other pollutant was correspondingly higher, and the daily range of pollutant concentration also increased. When air pollution was severe, the peak time of O3 appeared at 15:00, and the peak time of PM2.5 appeared at 19:00—20:00. The weather patterns that caused the complex pollution in Chaozhou were mainly the degenerative ridge of high pressure, anticyclone, subtropical high and degenerative ridge of high pressure, and uniform pressure field, which mainly appeared in autumn, winter and spring, and a few appeared in early summer. The four weather types appeared in different seasons, but generally speaking, sunny and dry weather was the main meteorological factor for the occurrence of complex pollution.