珠江三角洲城市群对雷暴的影响

利用2000—2007年广东省闪电定位仪所获得的地闪资料和广东省86个气象站所统计的雷暴日资料,对广东省(特别是珠江三角洲城市群区域)的雷暴日闪电频次变化进行了分析。结果表明:虽然珠三角城市群雷暴日与非城市群雷暴日相差不大,8年中变化也不大,但总闪远多于非城市群,总闪在8年中也有显著增长。珠三角城市群的单个雷暴的闪电频次要远多于非城市群区域,总闪增长也主要是单个雷暴的闪电频次的增长。而且,珠三角城市群对前汛期雷暴影响大,对后汛期影响相对较小。

THE EFFECTS ON THUNDERSTORMS OF THE URBANIZED CITY GROUP OF PEARL RIVER DELTA REGION

With the cloud-to-ground lightning flashes data obtained from lightning locators and statistical information on thunderstorm days by 86 stations in Guangdong province from 2000 to 2007, the variations of the frequency of lightning on thunderstorm days are analyzed for the province, especially for the urbanized city group of the Pearl River Delta region. The results showed that the group's total lightning number is more than that in areas that are not urbanized and the total number of flashes tends to increase significantly in the last 8 years, but the difference in thunderstorm days is not susbtantial between them and has little change in these 8 years. In urbanized group of the delta, the lightning frequency of the single thunderstorm is much more than that of nonurbanized areas. The increase of lightening flashes from single thunderstorms account for the bulk of the growth of total lightening flashes. The effects on the annually first rainy season of the urbanized city group of the Pearl-delta region season are more significant than on the annually second rainy season.