1971-2010年东北三省平均地面风速变化

利用1971-2010年逐月观测资料，分析东北三省年、季节和月平均地面风速变化的时空特征。结果表明：① 东北三省年平均地面风速变化呈显著递减趋势，变化速率为-0.23 m·s^-1·(10 a）^-1，1971-2000年（前30 a）、1981-2010年（近30 a）和1991-2010年（近20 a）平均地面风速变化均呈显著递减趋势，线性变化速率分别达-0.25 m·s^-1·（10 a）^-1、-0.20 m·s^-1_·（10 a）^-1和-0.17 m·s^-1_`（10 a）^-1，均通过了0.001显著性检验；② 近40 a东北三省各季和逐月平均地面风速变化趋势呈显著递减趋势，均通过了0.001显著性检验；春季递减速率最大，冬、秋季次之，夏季最小；③ 近40 a东北三省地面年平均风速的趋势变化除个别站点外，其他均呈现出比较一致的显著递减趋势，但最近20 a呈显著递减趋势的站点数在减少，递增趋势的站点数增多。

Change in Surface Mean Wind Speed of Northeast China during the Period of 1971 -2010

In this paper,the data of monthly surface wind speed in northeast China during the period from 1971 to 2010 were used to study the temporal and spatial change of average surface wind speed in three provinces(Liaoning,Jilin and Heilongjiang) in northeast China.The results are as follows:(1) For the entire period(40 years),the mean surface wind speed in these three provinces during the 40-year period was significantly decreased with a rate of-0.23 m·s-1·(10 a)-1.During the 30-year periods of 1971-2000 and 1981-2010 as well as the 20-year period of 1991-2010,mean surface wind speed was in a significant decrease trend with rates of-0.25 m·s-1·(10 a)-1,-0.20 m·s-1·(10 a)-1 and-0.17 m·s-1·(10 a)-1,and the values were all statistically significant at 0.001 confidence level;(2) For the entire study period,the average seasonal surface wind speed was significantly decreased,and the decrease was the most significant in spring,then in winter,fall and summer.All seasonal trends for the whole period were significant at 0.001 confidence level.The average monthly surface wind speed was also consistently decreased;(3) Average annual wind speed in northeast China in recent 40 years was significantly decreased except that at one or two stations.During recent 20 years,the average surface wind speed was in a decrease trend in most areas,but the sites with significant decrease trend were in a reduction,and those with increase trend were in an increase,especially in the central and western parts of northeast China in recent 10 years.