黑龙江省大气边界层不同高度风速变化

利用黑龙江省1961—2010 年哈尔滨、嫩江、齐齐哈尔、伊春4 个气象站探空和地面风速资料,分析了边界层内不同高度风速的气候学特征和时间变化趋势,获得以下结论:①黑龙江省边界层内不同高度年平均风速随高度增加而增大,10 m到300 m风速垂直递增率最大;风速在年内具有明显的季节性特征,各高度都是春季最大,近地面层冬季风速最小,其余高度夏季风速最小。②1961—2010 年,近地面10 m高度平均风速1970 年代最大,其后各年代风速逐渐减小,2000 年代风速最小;300、600、900 m高度,平均风速1980 年代最大,从1980 年代到2000 年代逐渐减小,300 m高度平均风速最小出现在1960 年代,600 m和900m最小出现在1970 年代。③1961—2010 年,近地面10 m高度平均风速呈明显减弱趋势,递减率为0.162 m/(s·10 a),递减趋势主要发生在1970 年代以后,但300、600 和900 m高度平均风速变化均不显著。④黑龙江省近地面风速变化趋势可能主要与观测环境改变和城市化等非自然因素影响有关,上层的风速变化则主要受大尺度大气环流变化的影响。

The Characteristics of Wind Speed Variation at Different Altitudes of Boundary Layer in Heilongjiang Province

Using the data of upper air and surface wind speed observed from Harbin, Nenjiang, Qiqihar and Yichun of Heilongjiang Province, from 1961 to 2010, the characteristics of variation of wind speed in boundary layers are analyzed. The following conclusions are drawn: 1) The annual mean wind speed increases with height from the ground to 900 m, and the distribution of wind speed at different time of the year has obvious characteristics of seasonal variation, with the maximum in springtime and the minimum in wintertime at near-surface layer, and the minimum in summertime at the remaining height layers; the maximum wind speed vertical increasing rate appears between 10 m and 300 m. 2) In 1961-2010, the largest mean wind speed at 10 m height is in the 1970s, and gradually decreases from the 1970s to the 2000s, with the smallest value occurring in the 2000s; at 300 m, 600 m, 900 m heights, the largest mean wind speed is in the 1980s, and wind speed gradually reduces from the 1980s to the 2000s, with the smallest value being in the 1960s at 300 m and in the 1970s at 600 m and 900 m. 3) During 1961- 2010, the mean wind speed at 10 m is weakening and the diminishing rate is 0.162 m/(s· 10a), and the trend occurs mainly after the 1970s. At 300 m, 600 m and 900 m, the mean wind speed trends are not significant. 4) It seems that the significant slowdown trends of the surface wind speed in Heilongjiang Province is mostly caused by the fast urbanization and the change of observational environment.