1981-2013年内蒙古地区风速的时空变化特征

Characteristics of Spatial and Temporal Changes of Wind Speed During 1981-2013 in Inner Mongolia Autonomous Region

利用内蒙古地区42个气象观测站1981-2013年共33年逐日地面常规风速资料,采用线性趋势、小波分析和M-K突变检验等统计方法,分析了该地区平均风速的时空变化特征.结果表明:内蒙古地区的平均风速呈西高东低的分布形势,逐月变化呈双峰型,春季风速最大,秋季次之,夏季和冬季风速最小;平均风速呈逐年减小的趋势,减小的速度为0.18m·s-1·(10a)-1,20世纪90年代下降最为明显,近年来下降趋势较缓;风速显著减小的地区主要分布在西部、中部,阴山一带以及东部地区风速呈弱上升趋势;四季变化趋势与年变化一致,其中夏季变化幅度最大,冬季最小.内蒙古地区平均风速在研究时段内存在着准4a、准6a的年际和准14a的年代际周期变化,突变检测表明平均风速在20世纪90年代出现了突变.

Based on the daily surface wind speed data of 42 meteorological observational stations in Inner Mongolia Autonomous Region,linear regression,Morlet wavelet analysis and M-K are used to study the spatial and temporal changes of wind speed in Inner Mongolia Autonomous Region.The results show that there is relatively higher wind speed in the west of Inner Mongolia Autonomous Region and lower in the east region;the curve of monthly change of wind speed turns out to be the bimodal pattern,which shows that the highest speed in spring and lowest in summer.The mean wind speed has tended to decrease,the value is 0.18 （m/s）/10a,the trend of decrease is distinct in 1990s,and in recent years the trend has been eased.The trend in four seasons is the same as annual mean,and the value of summer is highest,lowest in winter,the region of decrease is distributed in the middle and west of Inner Mongolia Autonomous Region,and the wind speed has a weak increase in east region.Oscillations with 4-year,6-year and 14-year periods can be detected in annual mean wind speed,and it suggests that the mutations of wind speed during 1981-2013 occur in 1991.