气象条件对兰州市近地面臭氧质量浓度的影响

The influence of meteorological conditions on near-surface ozone mass concentration in Lanzhou City

利用2016-2017年兰州市国家空气质量监测点连续的w(O3)资料分析了兰州市区的O3污染特征,利用2016年1月1日-2017年10月31日兰州市逐日的气象观测资料分析了w(O3)与气象要素之间的关系.结果表明,兰州市区w(O3)夏季最高(7月最高为134μg/m3),春季次之,冬季最低;2016-2017年兰州市区w(O3)呈逐年上升趋势;w(O3)空间分布特征显示,西固区O3污染最为严重,七里河区次之,城关区最低.自2016年以来兰州市区w(O3)和超标天数明显增加,2016年w(O3)均值为94μg/m3,超标天数15 d,2017年w(O3)均值104μg/m3,超标天数为38 d,是2016年的2.5倍.气象要素对w(O3)有着十分重要的影响,日照时数和气温与w(O3)呈显著正相关,相关系数分别为0.62、0.69,其中夏季高温对超标天数影响显著;相对湿度和风速与w(O3)呈负相关,充足的日照、高温、低湿、小风、无降水是造成w(O3)偏高的主要因素.

The characteristics of O3 pollution in Lanzhou City were analyzed using the daily w(O3)data collected from National air quality monitoring station from 2016 to 2017.The relationship between w(O3)and meteorological elements was also studied using the meteorological data.The results showed that w(O3)in Lanzhou City was the highest in summer(the highest in July being 134μg/m3),followed by spring and winter.The w(O3)in Lanzhou City was increasing from 2016 to 2017.The spatial distribution of w(O3)showed that the O3 pollution in the Xigu area was the most serious,followed by the Qilihe area.The lowest was in the Chengguan area.The w(O3)and the number of days in 2016 and 2017 exceeding the standard level increased significantly.The average w(O3)were 94 and 104μg/m3 respectively in2016 and 2017,and the numbers of days exceeding the standard level were 15 and 38 respectively in2016 and 2017.The number of days exceeding the standard in 2017 was 2.5 times of 2016.Meteorological factors had a significant impact on w(O3).The sunshine hours and temperature were significantly positively correlated with w(O3).The correlation coefficients were 0.62 and 0.69 respectively.The summer high temperature had a significant impact on the number of days exceeding the standard level,and the relative humidity and wind speed were negatively correlated with w(O3).Sufficient sunshine,high temperature,low humidity,small wind and no precipitation were the main factors causing a high w(O3)in Lanzhou City.