海口市臭氧污染特征

基于2013—2015年海口市4个空气质量自动监测站点数据,结合气象资料,分析了海口市O_3的污染特征。结果表明:海口市O_3总体优良,优良天数比例为99.4%,污染天数均为轻度污染;在良和污染天数中,O_3作为首要污染物的天数占40%,超过其他5项污染物占比。海口市10月O_3浓度最高。O_3月均浓度与温度呈负相关关系,同时与风向有密切关系:5—8月气温较高,以南风为主,O_3浓度较低;1月北风频率较高,易受外来污染传输作用,O_3浓度相对较高。O_3超标日以东北风为主,日变化并未呈现单峰型特征,12:00—22:00时段O_3浓度在10%范围内小幅变化。台风外围型和北方冷高压底部型是造成海口市O_3超标的2类典型天气形势。

Characteristics of Ozone Pollution in Haikou

Based on the data from four air quality automatic monitoring stations in Haikou from 2013 to 2015, combined with the meteorological data, the characteristics of ozone pollution in Haikou were analyzed. The results showed that the overall air quality of ozone was good in Haikou. The proportion of good and moderate days was 99.4%, and slightly pollution days accounts for 0.6%. The proportion of ozone as the primary pollutant was 40%, which was the highest among the major pollutants. The highest monthly concentration of ozone appeared in October. Monthly mean concentration of Ozone was negatively associated with temperature, and was closely related to the wind direction. Ozone concentration in Haikou was relatively low from May to August with predominant south wind and high temperature. On the contrary, monthly concentration of ozone was relatively high from October to January with predominant north wind, which was affected easily by the external pollution transporting. During the pollutant days, the predominant wind direction was northeast, and the diurnal variation didn''t show a single peak distribution, concentration of ozone slightly changed in the range of 10% from 12:00 to 20:00. Typhoon periphery and the northern cold high pressure bottom type were two typical weather situations which leaded to ozone pollutant in Haikou.