利用玛曲黄河源区气候与环境综合观测研究站的湍流资料,分析了青藏高原东部玛曲地区土壤冻融过程中近地层湍流统计特征的差异。结果表明,冻融过程中不同阶段近地层湍流输送特征表现出一定的差异性;各个阶段不稳定层结下无量纲化的风速分量脉动方差与稳定度符合1/3次方律,近中性条件下无量纲化的风速分量脉动方差近似为常数,水平方向上的风速分量方差随地表动力学粗糙度减小而呈现逐渐增大的趋势,垂直方向上的速度脉动方差变化不大,说明下垫面的物理特性对水平速度分量方差的影响比垂直方向明显;冻融过程中不稳定层结下无量纲化的温度、湿度和二氧化碳脉动方差与稳定度符合-1/3次方律,温度和湿度的拟合系数表现为冻结状态下的值小,而冻结前和融化后的值大。
Using the turbulence observation data from Maqu Yellow River Source Region Climate and Environment Observation and Research Station,the turbulence characteristics of atmospheric surface layer during soil freezing and thawing seasons in Eastern Qinghai-Xizang Plateau were analyzed.The main results show that the turbulence characteristics of atmospheric surface layer have been found differences in different periods of soil freezing and thawing processes.The normalized standard deviations of velocity components in unstable conditions increase with instability and obey a 1/3 power law during soil freezing and thawing processes.The normalized standard deviations of velocity components near neutral stratification are tend to constants.The constants of horizontal direction decrease with surface dynamic roughness length while that of vertical direction has small changes,which indicates that the physical characteristic of land surface has significant influence on the standard deviation of horizontal direction.The normalized standard deviations of temperature,specific humidity and carbon dioxide in unstable conditions decrease with instability and obey a-1/3 power law during soil freezing and thawing processes.The fitting coefficients of temperature and specific humidity in frozen period are smaller than that in unfrozen period.