现场海域水平扩散系数的探讨 Ⅱ．黄河三角洲埕北海域的计算

根据Ｔａｙｌｏｒ的湍流扩散理论和Ｈａｙ、Ｐａｓｑｕｉｌｌ提出的拉格朗日流和欧拉流的相关函数的相似性，用黄河三角洲埕北海域的实测资料，按四种不同方案计算出该海域的水平扩散系数和谱密度分布。指出：该海区潮流扩散系数主要受潮流的影响，其分布特征与潮流的分布基本一致，所求的水平扩散系数主要是由周期性的潮运动给予潮流扰动所致。方案４是通过富氏变换滤波消去了周期性潮流扰动，本方案计算的水平扩散系数是由周期为６ｈ以下的小尺度涡提供能量。

A STUDY ON THE HORIZONTAL DIFFUSION COEFFICIENT IN FIELD (E ) --CALCULATED VALUES IN THE CHENG-BEI SEA OFF THE YELLOW RIVER DELTA

Based on turbulent diffusion theory proposed by Taylor and the similarity between the autocorrelation function of Lagrangian current and that of Eulerian current proposed by Hay and Pasquill and using the observed data in the Cheng--bet Seaoff the Yellow River Delta this paper presents the calculated values of horizontal diffusion coefficient and the spectra in different time scales. The results show that the horizontal diffusion coefficient calculated by the first three schemes is mainly controlled by the tidal current. The energy of horizontal diffusion is provided mainly by the perturbation of tidal currents. The distribution of tidel currents is similar to that of the horizontial disffusion coefficient. The third scheme shows that thehorizontal diffusion is caused by small scale eddies with periods less than six hours.