广州市近地层大气的湍流微结构和谱特征

本文利用UVW脉动风速仪资料分析了广州市区近地层大气的湍流强度、相关系数、尺度和速度谱,并获得了不同稳定度条件下的速度谱模式.结果表明,城市近地层大气湍流在惯性副区接近局地各向同性、速度谱符合Kolmogorov相似理论;气流方向上下垫面粗糙度的增加,使沿海城市近地层大气湍流能量(特别是铅直方向)比平坦、均匀下垫面上的增加.

Microstructure and Spectral Characteristics of Turbulence in the Surface-Layer Atmosphere over Guangzhou

The intensities, correlation coefficients, scales and spectra of velocity components of turbulence in the atmospheric surface- layer in the city of Guangzhou are studied using data from an UVW anemometer. The models of velocity spectra in different stratified atmosphere are also approached. The results show that in the urban surface- layer,the turbulent behaviour is nearly consistent with the laws of local isotropy in the inertial subrange, the velocity spectra conform to Kolmogorov's similarity theory. The turbulent energy (especially for the vertical wind component) in the coastal city surface- layer, because of the increase of the surface roughness in the wind di -rection, is larger than that over flat and homogeneous terrain.