青藏高原大气边界层湍流特征量分析

ANALYSIS OF TURBULENT CHARACTERISTICS IN ATMOSPHERIC BOUNDARY LAYER OVER THE QINGHAI-XIZANG PLATEAU

采用１９７９年青藏高原气象科学实验资料，研究高原陆面上总体湍流输送系数ＣＤ和ＣＨ的特征及边界层高度受高原地形的影响。结果表明，用廓线法计算的高原上局地的ＣＤ和ＣＨ值比同样粗糙度长度条件下平原地区的值大得多，而且日较差也大于平原地区。主要是青藏高原地处内陆，气温强烈的日变化引起大气层结日变化加大所致；其次，地形复杂增强了机械湍流运动。这里的边界层高度也比平原地区通常出现的值要大得多。

The meteorological exploration data collected from the Qinghai-Xizang Plateau are used to analyse the variation of bulk transport coefficient C D and C H. The results show that the values of C D and C H are much higher on the Plateau than those on plain area, and the daily ranges are also higher, while the dynamical roughness lengths are almost the same. The main reason seems that the Qinghai-Xizang Plateau is located in inland, large variation of air temperature caused strong daily variation of atmospheric stratification. Secondly, complicated terrain enhances mechanical turbulent movement. The boundary layer height over the Qinghai-Xizang Plateau is also higher than that on plains.