山谷城市的近地层大气湍流谱特征

山谷城市地区的大气湍流结构研究至今报道很少.本文根据兰州市一次观测实验,对各风速分量谱、温度谱以及动量和感热通量的协谱进行了分析.结果表明,尽管仪器的安装高度较低(6.45m),湍谱特征仍与平坦均匀下垫面得到的一些典型结果基本一致,从而认为,在类似地区进行湍流通量等的直接观测时,对观测高度和地点的选择,可以不必象一些文献要求的那样高.

The Spectral Characteristics of Atmospheric Turbulence in an Urban Area of Complex Terrain

There are very few reports on the spectral characteristics of atmospheric turbulence in an urban area of complex terrain . This paper presents an observational study in Lanzhou City , analyses the spectra of velocity and temperature and the cospectra of momentum and heat flux . It is shown that even though the mounting height of the sensors was rather low (6.45 meters ) , the turbulence spectral characteristics still agree well with the results obtained under flat and uniform conditions . It concludes that the requirements for the site and height selection in the direct measurements of turbulence fluxes might not be so stringent as some authors mentioned.