福州近地层臭氧分布及其与气象要素的相关性

Distribution of ozone in land surface layer in Fuzhou and its relationship with meteorological factors

利用2009-2010年福州市近地层臭氧的连续观测资料,分析了其时空分布特征,并结合气象要素进行了相关性分析,找出了易导致臭氧浓度超标的天气类型。结果表明,在工业源、交通源较密集的监测点,臭氧浓度较高;臭氧浓度月分布呈"双峰型",峰值在5月、10月,谷值在1月;浓度的季节排序为秋季>夏季>春季>冬季,绝大部分浓度超标日出现在春末和夏季,冬季则没有;臭氧浓度日分布呈"单峰型",清晨开始明显上升,最高小时浓度出现在午后,夜里维持在相对稳定的低值区;臭氧浓度与温度、日照、太阳辐射显著正相关,与云量、相对湿度、降水量显著负相关,受偏南和偏东风影响时臭氧浓度较高,在SSE方位上小时浓度超标率最高;超标日天气型主要有变性冷高压、地面倒槽和锋前暖区等强暖性、且非常不利于污染物扩散的天气系统。

Based on the observation data of ozone in near surface layer of Fuzhou urban area from 2009 to 2010, the temporal and spatial distribution characteristics of ozone were studied. The correlation between ozone and related meteorological parameters, and the synoptic weather patterns which were prone to induce ozone concentrations to exceed the national air quality standard, were analyzed. Results indicate that： the ozone concentrations are higher in stations that are close to industrial zones and traffic hubs ; two peaks of ozone concentrations in a year appear in May and October respectively, and the valley appears in January. The sequence of seasonal ozone concentration distribution is autumn 〉 summer 〉 spring 〉 winter. The ozone pollution days always appear in late spring and summer. Diurnal variations of ozone concentration show the characteristic of a single peak, which begin to rise obviously in the early morning and reach peak values in the afternoon, and maintain low values at night. The ozone concentration has obvious positive correlation with temperature, sunshine hours and solar radiation, and has obvious negative correlation with cloud amount, relative humidity and precipitation. Ozone concentration is high while under the influence of southern wind and eastern wind, and the probability of hourly exceedance of the national air quality standard is the highest in the SSE azimuth. The typical synoptic situations that lead the ozone concentrations to exceed the standard are weathers that are warm and unfavorable for pollutants to disperse, such as the transformed cold high pressure, the ground inverse trough, and the warm sector ahead of fronts .