塔中春季晴天近地层温度、湿度和风速廓线特征

Characteristics of temperature, humidity and wind velocity profiles in the surface layer in sunshiny day in spring in the Taklimakan Desert hinterland

利用最新安装的塔中“80m观测塔梯度探测系统”资料，详细分析了塔中春季晴天近地层80m高度内平均温度、湿度和风速廓线日变化分布特征，得出以下一些结果：（1）温度廓线有夜间辐射型、早上过渡型、白天日射型和傍晚过渡型四种。夜间近地层大气层结稳定，呈逆温特征；最强逆温出现在凌晨06时，此时，80m高度温差为11．1℃。白天，近地层80m内温度递减率在2．7—5．2℃／100m之间，大气一直处于超绝热不稳定状态。（2）湿度廓线有日夜之分。夜间，30m以下比湿随高度增高急剧变小，30m以上比湿随高度增加而增大，大气呈逆湿特征。白天，比湿随时间一直逐渐变小。在近地层30—50m之间有一个厚度约20m的逆湿层，全天都存在。（3）风速廓线也有日夜之分。夜间稳定层结，廓线风速值以比对数关系更快的速度向上递增，曲线弯向风速轴。白天不稳定层结，廓线风速值以比对数关系较慢的速度向上递增，曲线弯向高度轴。只有在10m以下高度，日夜间的风廓线近似遵循对数律关系。

Using the latest data that gathered from the 80 m observing tower gradient detecting system in the hinterland of the Taklimakan Desert, the diurnal changing distribution characteristics of mean temperature, humidity and wind velocity profiles in the 80 m layer above the ground on sunshiny day in spring,2006 have been analyzed and some results have leen drawn ： （ 1 ） There are four kinds of temperature profile ： night radiation pattern, morning tran- sition pattern, daytime insolation pattern and evening transition pattern. At night, the atmospheric stratification is stable and appears a temperature inversion characteristic in the surface layer. The strongest inversion is at six o＇ clock before dawn and the temperature difference inside 80 m surface layer is 11.1 ℃ at that time. The temperature lapse rate within 80 m surface layer is between 2.7 ℃/100 m and 5.2 ℃/100 m,and the atmosphere is in a superadiabatic unstability state all the daytime. （2） Humidity profiles have a division of night profiles and day pro- files. At night, specific humidity decreases rapidly with the height increasing below 32 m,but above 32 m humidity is increasing with height rising, and the atmosphere presents a characteristic of moisture inversion. In daytime, the specific humidity is diminishing gradually with time changing. There is a layer of inverse humidity approximately 20 m thick between the height 30 m and 50 m in the surface layer all day. （ 3 ） Wind velocity profiles is also divided into day profiles and night profiles. At night,the wind speed value of wind velocity profiles increases at a quicker rate than the logarithm relation and the curves bend to the wind speed axis. In daytime ,the wind speed value increases at a slower rate compared to the logarithm relation and the curves bend to the altitude axis. Only below 10 m height, the wind profiles approximately follow the logarithm law relations in daytime and at night.