2019-2020年上海地区空气质量变化特征及气象影响因素分析

Analysis of air quality change characteristics and meteorological influencing factors in Shanghai from 2019 to 2020

利用2019-2020年上海地区6种空气污染物小时浓度和逐日空气质量分指数(IAQI)的监测资料,统计分析了上海地区空气质量变化特征及其气象因素的影响。结果表明,2020年上海地区空气质量优良率达86.9%,空气质量状况优于2019年。上海地区AQI具有冬季最差,秋季最好的季节特征,最主要的污染物已由过去的PM_(2.5)转变为O_(3)。分析O_(3)和PM_(2.5)浓度随时间的变化发现,O_(3)浓度一天中存在一个峰值和一个谷值,而PM_(2.5)浓度则有两个峰值和一个谷值;从逐月变化来看,O_(3)浓度呈现春夏高,秋冬低的季节特征,而PM_(2.5)则呈现夏秋低,冬春高的季节特征。地面风向风速、气温、日照和降水对上海地区O_(3)和PM_(2.5)浓度变化具有重要的影响。

Based on the monitoring data of hourly concentrations of six air pollutants and daily air quality sub index(IAQI) in Shanghai from 2019 to 2020, the variation characteristics of air quality and the influence of meteorological factors in Shanghai were statistically analyzed. The excellent rate of air quality in Shanghai reached86.9% in 2020, and the air quality was better than that in 2019. AQI in Shanghai has the seasonal characteristic that AQI is the worst in winter and best in autumn. The main pollutants have changed from PM_(2.5)to O_(3). Analyzing the changes of O_(3)and PM_(2.5)concentrations with time, there was a peak and a trough in the O_(3)concentration in a day,while the PM_(2.5)concentration had two peaks and a trough. From the month-to-month change,O_(3)concentration showed seasonal characteristics of high in spring and summer, low in autumn and winter, while PM_(2.5)showed seasonal characteristics of low in summer and autumn, high in winter and spring. Surface wind direction, wind speed, temperature, sunshine and precipitation had important effects on the changes of O3 and PM_(2.5)concentrations in Shanghai.