塔中春季阴天近地层风速、温度和湿度廓线特征分析

Characteristics of Wind Velocity,Humidity and Temperature Profiles near Surface Layer on a Cloudy Day in Spring in the Hinterland of Taklimakan Desert

利用塔中最新安装的80 m梯度观测塔探测系统采集的资料,详细分析了2006年4月2日1次阴天天气时塔克拉玛干沙漠腹地近地层风速、温度和湿度廓线演变特征,并与典型晴天廓线做了对比,得到以下结果:(1)阴天,夜间风速廓线风速值随高度增高而增大,但不是以对数增长,而是以比对数关系更快的速度增长;白天,风速很小,近地层10 m上下廓线分布规律各异;(2)温度廓线有夜间辐射型、早上过渡型、白天日射型及傍晚过渡型4种类型,与晴天类似;(3)比湿廓线存在一个极小值,其出现高度以上比湿随高度增加而增加,廓线呈逆湿特征,极小值出现高度以下比湿随高度减小而增加。

By using the latest data obtained from the 80 m observing tower for meteorological factors detecting in the hinterland of Taklimakan Desert, the evolution characteristics of the wind velocity, temperature and humidity profiles near the surface layer there on a cloudy day （April 2,2006） were analyzed in detail, and these profiles were compared with those of the typical sunshiny day there. Resuhs are as follows： （ 1 ） On cloudy day, the value of wind speed is increasing with height at night but its change doesn＇ t obey the logarithmic law, it grows at a faster rate; in the daytime the wind speed is small,the distributions of wind velocity profiles above and below 10 m near the surface layer are rather different at each observational time; （2）Observed temperature profiles on cloudy day are classified into four types： radiation cooling at night, transition from night to daytime in early morning, insolation in the daytime, transition from daytime to night, respectively, they are similar to those of sunshiny day; （3）There is a minimum in specific humidity profiles,above the height where the minimum appears the specific humidity rises with height increase and appears a ＂ moisture inversion＂ phenomenon, and below that height the specific humidity rises with height decrease.