宜都市PM2.5与O3季节性分布特征及潜在源区分析

为了解宜都市PM_2.5与O₃的污染特征及潜在来源,利用宜都市2020年3月至2022年2月在线监测数据及气象数据,对宜都市PM_2.5与O₃质量浓度变化特征、气象影响因素及潜在源区进行了分析,结果表明:宜都市PM_2.5质量浓度冬高夏低,日变化呈双峰特征,O₃质量浓度夏高冬低,日变化呈单峰特征。高湿、静稳的气象条件以及较强偏北风作用下的区域污染传输对PM_2.5污染有重要影响,高温以及中湿度对O₃污染过程有重要作用。春、夏、秋季偏南方向气流轨迹占主导,且携带较高的污染物浓度,冬季来自湖北东北及西南方向的气流占比较高且携带的PM_2.5浓度较高;宜都市PM_2.5、O₃的潜在源区具有季节性差异,总体来看,主要分布在河南南部、湖北东部及湖南的北部区域。

Distribution Characteristics and Potential Source Areas of PM2.5 and O3 in Different Seasons in Yidu City

To study the pollution characteristics and potential sources of PM_2.5 and O₃ in Yidu City in different seasons,using the online monitoring data and meteorological data of Yidu City from March 2020 to February 2022, the seasonal variation characteristics,meteorological influencing factors and potential pollution sources of PM_2.5 and O₃ mass concentrations in Yidu City were analyzed. The results showed that the diurnal variation of PM_2.5 mass concentration in Yidu City showed a bimodal characteristic,and the seasonal variation of concentration was high in winter and low in summer. The diurnal variation of O₃ mass concentration showed a unimodal characteristic, and the seasonal variation of concentration was opposite to that of PM_2.5. The meteorological conditions of high humidity, static stability and regional pollution transmission of strong northerly wind had important effects on PM_2.5 pollution, while high temperature and moderate humidity had important effects on ozone pollution process. Southerly air flow in spring,summer and autumn was dominant and carried higher pollutant concentration. In winter,air flow from northeast and southwest of Hubei province took a higher proportion and carried higher PM_2.5 concentration. The potential source areas of PM 2. 5 and O₃ in Yidu city had seasonal differences. Generally speaking,they were mainly distributed in southern Henan Province,eastern Hubei Province and northern Hunan Province.