塔中春季阴天近地层风速、温度和湿度廓线特征分析

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。

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

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.Results 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.