Turbulence Intensity and Turbulent Kinetic Energy Parameters over a Heterogeneous Terrain of Loess Plateau  

作　　者：YUE Ping ZHANG Qiang WANG Runyuan LI Yaohui WANG Sheng 

机构地区：[1]Key Laboratory of Arid Climatic Change and Reducing Deserter of Gansu Province,Institute of Arid Meteorology,China Meteorological Administration

出　　处：《Advances in Atmospheric Sciences》2015年第9期1291-1302,共12页大气科学进展（英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2012CB955304);the National Natural Science Foundation of China(Grant Nos.41075008 and 40830957);the Special Financial Grant of China Postdoctoral Science Foundation(Grant No.2013T60901);the Arid Meteorology Foundation of the Institute of Arid Meteorology of the China Meteorological Administration(Grant No.IAM201408);the Ten Talents Program of Gansu Meteorology Bureau

摘　　要：A deep understanding of turbulence structure is important for investigating the characteristics of the atmospheric boundary layer,especially over heterogeneous terrain.In the present study,turbulence intensity and turbulent kinetic energy（TKE）parameters are analyzed for different conditions with respect to stability,wind direction and wind speed over a valley region of the Loess Plateau of China during December 2003 and January 2004.The purpose of the study is to examine whether the observed turbulence intensity and TKE parameters satisfy Monin–Obukhov similarity theory（MOST）,and analyze the wind shear effect on,and thermal buoyancy function of,the TKE,despite the terrain heterogeneity.The results demonstrate that the normalized intensity of turbulence follows MOST for all stability in the horizontal and vertical directions,as well as the normalized TKE in the horizontal direction.The shear effect of the wind speed in the Loess Plateau region is strong in winter and could enhance turbulence for all stability conditions.During daytime,the buoyancy and shear effect together constitute the generation of TKE under unstable conditions.At night,the contribution of buoyancy to TKE is relatively small,and mechanical shearing is the main production form of turbulence.A deep understanding of turbulence structure is important for investigating the characteristics of the atmospheric boundary layer,especially over heterogeneous terrain.In the present study,turbulence intensity and turbulent kinetic energy（TKE）parameters are analyzed for different conditions with respect to stability,wind direction and wind speed over a valley region of the Loess Plateau of China during December 2003 and January 2004.The purpose of the study is to examine whether the observed turbulence intensity and TKE parameters satisfy Monin–Obukhov similarity theory（MOST）,and analyze the wind shear effect on,and thermal buoyancy function of,the TKE,despite the terrain heterogeneity.The results demonstrate that the normalized intensity of turbulence follows MOST for all stability in the horizontal and vertical directions,as well as the normalized TKE in the horizontal direction.The shear effect of the wind speed in the Loess Plateau region is strong in winter and could enhance turbulence for all stability conditions.During daytime,the buoyancy and shear effect together constitute the generation of TKE under unstable conditions.At night,the contribution of buoyancy to TKE is relatively small,and mechanical shearing is the main production form of turbulence.

关 键 词：heterogeneous terrain turbulence intensity turbulent kinetic energy Monin–Obukhov similarity function 

分 类 号：P425.2[天文地球—大气科学及气象学]