Gustiness and coherent structure under weak wind period in atmospheric boundary layer

作     者：Li Qi-Long Cheng Xue-Ling Zeng Qing-Cun Li Qi-Long;Cheng Xue-Ling;Zeng Qing-Cun

作者机构：State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China 

出 版 物：《Atmospheric and Oceanic Science Letters》 (大气和海洋科学快报（英文版）)

年 卷 期：2016年第9卷第1期

页      面：52-59页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：supported by the national natural Science Foundation of China(40830103 and 41375018) the national Basic Research Program of China(2010CB951804) the Research Program of the Chinese Academy of Sciences(XDA10010403) 

主　　题：Atmospheric boundary layer gusty wind coherent structure weak wind downward flux of momentum 

摘      要：Statistical analysis of turbulent and gusty characteristics in the atmospheric boundary layer under weak wind period has been carried *** data used in the analysis were from the multilevel ultrasonic anemometer-thermometers at 47 m,120 m,and 280 m levels on Beijing 325 m meteorological *** time series of 3D atmospheric velocity were analyzed by using conventional Fourier spectral analysis and decompose into three parts:basic mean flow(period 10 min),gusty disturbances(1 min period 10 min)and turbulence fluctuations(period 1 min).The results show that under weak mean wind condition:1)the gusty disturbances are the most strong fluctuations,contribute about 60% kinetic energy of eddy kinetic energy and 80% downward flux of momentum,although both the eddy kinetic energy and momentum transport are small in comparison with those in strong mean wind condition;2)the gusty wind disturbances are anisotropic;3)the gusty wind disturbances have obviously coherent structure,and their horizontal and vertical component are negatively correlated and make downward transport of momentum more effectively;4)the friction velocities related to turbulence and gusty wind are approximately constant with height in the surface layer.