青岛市春季一次臭氧污染过程特征及成因分析

Characteristics and Cause of an Ozone Pollution Process in Qingdao in Spring

该文利用2018年5月22-25日春季一次O_(3)污染过程的监测数据,分析了青岛市O_(3)浓度的时空变化规律及污染成因。结果表明,23日、24日为污染日,O_(3)-8 h浓度分别为172、210μg/m^(3),气象特征表现为高温、强太阳辐射、弱西南风、相对湿度70%左右,无降水;O_(3)小时浓度呈现单峰型变化规律,午后16时左右达全天峰值。空间分布显示,23日、24日午后青岛市高空0.5 km以下范围O_(3)污染较严重,23日夜间高空2 km处发现O_(3)传输过程,并逐渐沉降至地面,导致24日浓度更高;23日青岛市区O_(3)污染程度较郊区偏高,来源主要为本地生成,24日在本地生成和高空传输沉降的共同影响下,O_(3)浓度进一步升高,且市区升幅更显著。此次O_(3)污染过程主要受本地生成及西南方向区域污染传输的共同影响。

Based on the monitoring data of an O_(3)pollution process on May 22-25,2018,the spatial-temporal distribution and pollution cause in Qingdao was analyzed.The results showed that May 23 and 24 were pollution days,and the O_(3)-8 h concentration was 172μg/m^(3)and 210μg/m^(3)respectively.The meteorological characteristics were high temperature,intensive solar radiation,weak west-south wind,relative humidity about 70%without precipitation.O_(3)hourly concentration showed a single-peak curve,reaching the whole day peak at 16 o’clock in the afternoon.The spatial distribution showed that O_(3)pollution below 0.5 km was more serious in the afternoon on May 23 and 24,and the O_(3)transmission process was found at a height of 2 km at night on May 23 gradually settled to the ground,causing higher concentration on May 24.The O_(3)pollution level in urban area was higher than that in suburbs on May 23,and the source was mainly local generation.Under the combined influence of local generation and high-altitude transmission settlement,the O_(3)concentration further increased on May24,and the urban area increased more significantly.The O_(3)pollution process was mainly caused by the local generation and the regional pollution transmission from the southwest.