Analyses of Turbulence Parameters in the Near-Surface Layer at Qamdo of the Southeastern Tibetan Plateau
BIAN Lingen (卞林根), XU Xiangde (徐祥德), LU Longhua (陆龙骅),GAO Zhiqiu(高志球), ZHOU Mingyu (周明煜), and LIU Huizhi (刘辉志) Chinese Academy of Meteorological Sciences, Beijing 100081 National Marine Environment Forecast Center, Beijing 100081 Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029
The characteristics of the turbulence spectrum, turbulence variance, and turbulence flux at Qamdo over the Southeastern Tibetan Plateau measured during the TIPEX experiment from 18 May to 30 June 1998 are analyzed by the eddy correlation method. During periods of intense convection, most of the spectra of the 3D winds, temperature, and humidity follow a power law with a slope of -2/3. The normalized variances of the 3D winds in relation to z/L satisfy the similarity law but the normalized variances of temperature and humidity are related to z/L by a -1/3 power law only in unstable conditions. In near-neutral stratification, u/u* and v/u* at Qamdo and Gerze are nearly constant in rugged terrain and w/u at Qamdo and Gerze is similar to the value found in plains, which indicates that the, effects of landform on vertical turbulence is not significant over the southeast and western Tibetan Plateau. During the dry period, the sensible heat dominates, comprising 81% of the heat intensity, with the other 19% being latent heat; during the wet period on the other hand, the latent heat accounts for about 64% of the available energy and the sensible heat only around 36%. The maximum intensity of the heating of air occurs in the middle of the Plateau during the summertime.