摘要
利用"西北干旱区陆气相互作用野外观测实验"加强期在甘肃省敦煌市气象站进行的风、温、湿探空观测资料,分析了西北典型干旱区大气边界层的结构特征和变化规律。结果表明,大气边界层厚度总体而言明显偏高,对流边界最高层厚度可超过4000m,稳定边界层也在1000m左右的高度;2750m附近为风向转变高度,其下全为偏东风,其上全为偏西风,这个风向转变高度有一定日变化,在观测的9天内每天的日变化规律保持了很好的一致性;边界层风速切变较大,大多数时候有低空东风急流出现,急流最强可达到近20m·s-1,急流高度在500m左右;边界层内比湿廓线有时在大约500m高处出现逆湿,一般以夜间更为显著。
Using the sonding data of wind, temperature and humidity in Dunhuang meteorological station during the intensive period of 'Land-atmosphere interaction field experiment over arid region of Northwest China from end of May to early June 2000, the structure characteristics and change laws of the atmosphere boundary layer over arid region of Dunhuang are analyzed. The results show that the mean value of the atmosphere boundary layer thickness is obviously more higher than usually. The biggest depth of the convective boundary layer exceeds 4000 m, the stable boundary layer depth is 1000 m or so. The turning height of wind direction is at about 3000 m high. The wind was blowing easterly in lower layers and west in upper layers. There is some diurnal variation in the turning height, and the diurnal variation of all nine days is mainly identical. The velocity shear is the bigger in boundary layer. In most time the low-level east jet appears, its intensity is close to 20 m·s^(-1) and its height is about 500 m. The humidity inversion is below about 500 m and it appears mainly in the evening.
出处
《高原气象》
CSCD
北大核心
2004年第5期587-597,共11页
Plateau Meteorology
基金
国家自然科学基金项目(40175004)
国家重点基础研究发展规划项目"我国重大气候灾害形成机理和预测理论的研究"(G1998040906)共同资助.
关键词
敦煌戈壁
边界层厚度
低空急流
风向转变高度
大气逆湿
Dunhuang Gobi
Boundary layer thickness
Low-level jet
Turning height of wind direction
Atmospheric humidity inversion
