近40年那曲地区日照时数和风速变化特征

Variation Characteristics of Sunshine Duration and Wind Velocity in Naqu,Xizang for Recent 40 Years

利用那曲地区6个气象站1961—2000年逐日日照时数和风速资料,采用常规统计方法和墨西哥帽小波变换分析那曲地区近40年日照时数和风速的地理分布以及年内、年际、年代际变化规律。主要结果是:那曲大部分地区,年总日照时数大于2550小时,年平均风速大于4m·s-1;近40年那曲地区春季、夏季、秋季、冬季、生长季(5—9月)和年6个时段的日照时数均呈减少趋势;风速冬季呈减少趋势,其它时段呈增加趋势;6个时段的90年代日照和风速都小于80年代;2000—2005年日照时数和风速继续减小的可能性比较大。

Based on the conventional statistic methods and Mexican hat wavelet, the geographical distribution of sunshine duration and wind velocity and their annually, and interdecadal changes in recent 40 years are analyzed using daily sunshine duration and wind velocity data of 6 stations in Naqu from 1961 to 2000. The main results are as follows： （1） In the most of places of Naqu, the annual sunshine duration are more than 2550 hours and average wind velocity are higher than 4m·s^-1. （2） The sunshine duration in spring, summer, autumn, winter, growing season （from May to September） and a year all decreased in recent 40 years. （3） The wind velocity in winter decreased and the wind velocity in other 5 periods all increased. （4） The sunshine duration and wind velocity in 1990＇s were smaller than that in 1980＇s for all 6 periods. （5） The sunshine duration and wind velocity from 2000 to 2005 could continue to decrease.