1986年夏季西藏东部近地层湍流输送特征的分析

本文以1986年夏季西藏高原气象实验(TIPMEX-86)期间获得的资料为基础,运用廓线方法,计算了实验期间感热、潜热和动量湍流通量并分析了与通量输送有关因子的变化。分析结果表明,各种湍流通量都有明显的日变化、日际变化和旬变化。7月份感热通量比6月份大约减少了2/3以上。计算得出那曲6月13—28日拖曳系联C_d的平均值为0.0052,同期感热通量的整体输送系数C_h为0.0075;而拉萨6月11日—7月20日C_d的平均值为0.0056,同期C_h的平均值为0.0085。根据整体输送系数和各种有关因子的关系分析表明,C_d,C_h不可能用一个常数代表,它们不仅仅是风速的函数,而且其变化还包含了稳定度、风速梯度、温度梯度的综合效应。

THE CHARACTERS OF THE TURBULENT TRANSPORTS IN THE SURFACE LAYER OVER THE EASTERN TIBET DURING THE SUMMER 1986

The turbulent fluxes for sensible and latent heat and momentum are computed and analyses are described which include the factors in terms of the fluxes,with the profile methods,based on the data from the Tibetan Plateau Meteorological Experiment 1988.It is shown that the various fluxes have evidently diurnal amplitudes,and every decade mean diural variations are very different.The sensible heat flux is less about 2/3 in July than that in June.The results indicate that C_d,the drag coefficient,and C_h,the bulk transfer coefficient of sensible heat,are 0.0052 and 0.0075 respectively.which are averaged for the periods 13 to 28 in June for Nagqu.But for Lhasa data,C_d is 0.0058,and C_h is 0.0085,averaging periods from June 11 to July 20.It is found that C_d and C_h not only are the functions of wind velocities,but also are influenced by both stability conditions and wind and temperatureradients.