河西地区非均匀下垫面的大气变性过程

THE VARIABILITY PROCESS OF ATMOSPHERE OVER HETEROGENEOUS UNDERLYING SURFACE IN HEXI REGION

利用ＨＥＩＦＥ野外观测资料，分析了河西地区黑河流域夏半年下垫面动力和热力特性的不均匀性；并以个别具有一定代表性的晴天观测资料为例，客观地分析了绿洲与沙漠或戈壁下垫面突变所产生的近地层大气变性过程；初步解释了绿洲近地层逆温和沙漠或戈壁近地层逆湿的形成机制。

In this paper,the dynamic and thermodynamic characteristics of the underlying surface in Heihe River basin of Hexi region in summer are analysed with the data observed in HEIFE (Heihe Earth-Atmosphere Interaction Field Experiment). Taking the data observed on a canonical clear day as an example,the process of the variability of atmosphere,which result from the sudden change of underlying surface from desert(or Gobi) to oasis or from oasis to desert (or Gobi) is given. From this,the mechanisms resulting in the inverse temperature gradient of surface layer over oasis and the inverse humidity gradient of surface layer over desert(or Gobi) have been explained primitively. Besides,the processes of water vapour transport over oasis and desert (or Gobi) is shown.