南岳高山站1953—2010年风的气候特征分析

An Analysis of the Climatic Variations in Winds Observed at the Nanyue Mountain Observatory During 1953—2010

利用1953—2010年南岳高山站风观测资料,采用趋势分析、矢量分解、小波分析及M-K突变分析等方法,分析了南岳站风的气候变化特征。结果表明:(1)南岳山盛行风具有明显的季节变化,春夏盛行西南风,秋冬盛行北风。(2)年平均风速呈显著减弱趋势,减小速率为-0.25 m·s^(-1)/10年,四季中夏季变率最大,冬季变率最小,夏、冬季分别从20世纪70年代后期和80年代后期开始风速发生了明显减弱。风矢量分解后显示,经、纬向风速均呈减弱趋势,经向风速的减小速率远大于纬向,南、北风分量风速都在减弱,北风分量风速减小速率明显大于南风分量,西、南风分量仅在夏季显著减弱,而北风分量在春、秋、冬季都呈显著减弱趋势。分析还发现,南岳山风场年代际变化特征显著,年以及冬季平均风速16年周期振荡在20世纪90年代后发生了明显转折,与同时期的大气环流变化趋势基本一致。

Based matlc varl analysis, atlons on the 1953--2010 meteorological records at the Nanyue of winds are examined by using the trend analysis, the ve Mountain Observatory, ctor decomposit and the Mann-Kendall test statistics. The results can be shown that.. （1） the ion, th prevaili over the Nanyue Mountain exhibit significant seasonal variations, with the prevailing wind bei westerly in spring and summer and being northerly in autumn and winter; （2） annual mean wind perienced statistically significant decreasing at an averaged rate of -0.25 m .s^-1/decade, with e the cli- wavelet ng ng winds south- speed ex- the maxi- mum trend occurring in summer and minimum trend in winter. In addition, vector decomposition analysis indicates that both meridional and zonal wind speeds show decreasing trends, with the meridional declining faster than the zonal declining. For the meridional slowdown, the north wind decrease is faster than the south wind. Statistically significant declining trends in the west and south wind components can only be detected in summer, while significant slowdown in the north wind can be found in all seasons except in summer. Analysis also indicates that winds over the Nanyue Mountain exhibit significant interannual and interdaeedal variations. Oscillations with 16-year periods can be detected both in annual mean and winter wind speeds, but they are remarkably changed after the 1990s. It is suggested that the interdecadalvariation of wind speed may be closely associated with the variations of large-scale East Asian monsoon systems.