大连市臭氧污染特征及典型污染日成因

通过对大连市区10个空气监测子站的监测数据进行分析,探讨了大连市臭氧污染的时空分布、气象条件对臭氧污染的影响,对臭氧污染日进行了归类分析。结果表明,大连市臭氧污染主要出现在4—10月。在强紫外辐射、高温、低湿、低压和低风速的气象条件下,监测点位的臭氧浓度较高。臭氧污染日的日变化分为单峰型、双峰型和夜间持续升高型3种类型。通过对2015年的一次高浓度臭氧污染过程的气象条件、污染物浓度和污染气团轨迹进行分析,发现臭氧浓度在夜间持续升高现象与区域输送密切相关。

The Characteristics of Ozone Pollution and Causes of A Typical Ozone Pollution Episode in Dalian

The spatiotemporal patterns of ozone pollution, effects of meteorological conditions on ozone concentrations, and the classifications of ozone daily variations in Dalian were analyzed based on the observation data from local 10 national monitoring stations. The results showed that ozone pollution mainly occurs from April to October. Higher observed ozone concentrations in Dalian often associate with strong UV light, high temperature, low humidity, low pressure, and low wind speed conditions. Based on daily variations of ozone concentrations, the ozone pollution days are classified as normal single peak pattern, double peaks pattern, and rising at night pattern. The ozone rising at night pattern is found to be closely related to the regional transport effect via analyzing meteorological factors, variations of pollutant concentrations, and back trajectories of polluted air mass from a typical ozone pollution episode in 2015.