基于日均UV判别法统计的湛江市霾日特征

Characteristics of Hazy Days in Zhajiang Statistically Determined with Daily Averaged UV Discrimination

根据湛江市6个地面观测站1961—2014年的气象资料,采用日均UV法(U为相对湿度,V为能见度)、线性趋势分析、Mann-Kendall突变检验、小波分析等方法,研究了湛江市霾日的时空变化特征。结果表明:1961—2014年湛江市年平均霾日10.4 d,年霾日以每年0.5 d的速率显著增加。20世纪60年代和90年代霾日较少,20世纪80年代和21世纪霾日较多。冬季最多,1和12月的霾日之和占全年的39.4%;春季、夏季霾日较少,5—8月霾日之和仅占全年的5.8%。湛江市霾日在1977年左右发生突变性增加。霾日在20世纪80年代具有显著的2~4年周期,2000年以来具有3~5年的显著周期。霾日及其增加速率高值区集中在湛江城区、吴川、廉江;低值区集中在遂溪、雷州、徐闻。

With meteorological observations for 1961 -2014 from six surface stations in Zhanjiang and the methods of daily averaged U （ relative humidity） and V （visibility） discrimination, linear tendency anal- ysis, Mann-Kendall abruptness test and wavelet analysis, the spatiotemporal variations of hazy days in the city were studied. The result is shown as follows. The annual mean number of hazy days of Zhanjiang was 10.4 d during this period, which significantly increased at a rate of 0.5 d per year. The number of hazy days was relatively small in the 1960s and 1990s while it is relatively large in the 1980s and 2000s. Winter was the season with the most number of hazy days （ NHD）, in which the sum of January and December took up 39.4% of the annual total, while spring and summer are the seasons with the least number, in which the sum of May through August was only 5.8% of the yearly total. For the city, the NHD had an abrupt change around 1977. It had a significant period of 2 to 4 years in the 1980s and one of 3 to 5 years in the 2000s. The NHD and its areas of high values concentrated in the urban areas of Zhanjiang, Wuchuan and Lianjiang, and the areas of low values in Suixi, Leizhou and Xuwen.