近50年西北地区风速的气候变化特征

利用西北地区125个气象观测站1960～2009年的日平均风速资料,采用线性趋势分析、M-K突变检验和EOF分析等方法,研究了近50年西北地区风速的气候变化特征。结果表明,西北地区风速存在北大南小的分布特点,大部分地区的年平均风速在1～4 m/s,小值区位于新疆的塔里木盆地,大值区主要分布在我国中蒙边境地区;年平均风速的减小率均在0.1 m/（s·10 a）以上,其中新疆的西北部、新疆的东南部和内蒙古的西部风速减小趋势最显著;风速的月变化呈明显的单峰型分布,4月份的风速最大;年平均风速整体呈减小趋势主要是由于日平均风速〈3 m/s的日数呈显著增加趋势;青海、甘肃和新疆均出现突变点,突变时间分别为1993、1982和1981年;风速主要呈现出整体一致和＂负正负＂的变化特点。

Climate Change Characteristic of Wind Speed in Northwest of China in Recent 50 Years

Based on the daily mean wind speed from 125 meteorological stations in Northwest of China from 1960 to 2009 and the methods of linear fit,Mann-Kendall test and EOF decomposition,climate change characteristic of wind speed in northwest of China in recent 50 years were analyzed.The results showed that there is higher wind speed in the north and smaller wind speed in the south and the wind speed of the most areas is 1-4 m/s.The smallest wind speed areas are in the Tarim Basin and the biggest are in the borders of China and Mongolia;the wind speed in April is the biggest in twelve months in a year;the annual mean wind speed has tended to decrease,the value is above 0.1 m/(s·10a).This is because the days of over 3 m/s is decreasing;meanwhile,the sudden change of wind speed are found in Xinjiang,Gansu and Qinghai;the annual mean wind speed is taking on two climate change characteristics of "consistency in all zones" and "difference in east,west and central".