1960年至2004年南京市风速变化及其成因研究

Changes in wind speed and its causes in Nanjing During the Period of 1960—2004

利用南京、高淳、江宁、江浦、六合、溧水六个地面站1960年至2004年逐日平均风速数据资料,分析了南京市平均风速的时空变化特征及其可能原因。其结果表明:近45年来南京市年平均风速为2.61 m/s,最大平均风速出现在3月,为3.08 m/s,十月的平均风速最小,为2.45 m/s。一年四季中,春季的平均风速最大,为2.93 m/s,秋季平均风速最小,为2.50 m/s,呈现出"春季大,秋季小"的季节分布类型。近45年间各季节与年平均风速的年代际变化趋势基本一致,都呈现出波动性变化及总体减弱的趋势。在空间上,南京市平均风速呈现出"南大北小"的地理分布格局。风速的变化,主要是由于全球气候变暖下中国乃至亚洲大气环流的变化而引起的局地环流的变化。此外,强冷空气南下次数和强度的减小、台风的减少、观测环境的影响、仪器性能的差异以及统计时次的变更等也是引起南京市风速变化的原因。

Use Nanjing, Gaochun,Jiangning,Jiangpu,Liuhe,Lishui six meteorological stations 1960--2004 daily average wind speed and temperature observations,analysis the temporal and spatial characteristics and its possible causes of Nanjing wind speed. Their results indicate that Nearly 45 years,the average wind of 2.61 m/s in Nanjing city maximum average wind speed appears in the March,3.08m/s,minimum average wind speed of October,2.45 m/s. During all the year round,average wind speed maximum in spring,2.93m/s,minimum average wind speed in the autumn,to 2.50m/s.Show＂spring and autumn a small＂type of seasonal distribution.Annual average wind speeds of nearly 45 years in various seasons and Inter--decadal change trend of basically the same, were showing fluctuations and overall weakening of trend,In space,the average wind speed in Nanjing showing a＂South great northern small＂geographical distribution.Changes of wind speed,mainly due to the global warming caused by the change of atmospheric circulation in China and Asia under local circulation changes. In addition,strong southward cold air observation of frequency and intensity is reduced,the difference between environment,instrument performance and statistical changes is caused when wind speed causes the change of Nanjing.