Tidal currents, energy flux and bottom boundary layer thickness in the Clyde Sea and North Channel of the Irish Sea
Tidal currents, energy flux and bottom boundary layer thickness in the Clyde Sea and North Channel of the Irish Sea
复制标题
克莱德海和爱尔兰海北海峡的潮汐流、能量通量和底部边界层厚度
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
R. Player
中科院分区：
文献类型：
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作者：
A. M. Davies;P. Hall;M. J. Howarth;P. Knight;R. Player
克莱德海和邻近的爱尔兰海北海峡的高分辨率三维模型用于计算该地区的主要日潮和半日潮汐、相关的能量通量和底部边界层的厚度。最初，通过对计算出的该地区的潮汐高度和洋流与 M2、S2、N2、K1 和 O1 潮汐的广泛数据库进行详细比较来评估模型的准确性。随后，该模型用于计算该区域的潮汐能通量矢量。这些表明主要能量通量仅限于北海峡地区，很少有能量通量进入克莱德海。与北航道观测到的能量通量的比较表明，其跨航道分布及其强度对高程和海流之间的相位差特别敏感。因此，由于模型开放边界值的不确定性阶数的微小变化而导致这些参数的计算值的微小变化，可以显着影响计算的能量通量。该区域底部边界层的厚度是使用多种公式计算的。根据所采用的定义，用于确定其厚度的经验系数 C 在 0.1 至 0.3 范围内变化，与文献中的值非常一致。在北航道，边界层厚度占据了整个水深，因此海底产生的潮汐湍流使该区域保持良好的混合。在克莱德海，边界层厚度只占深度的一小部分，因此该区域分层。
A high-resolution three-dimensional model of the Clyde Sea and the adjacent North Channel of the Irish Sea is used to compute the major diurnal and semidiurnal tides in the region, the associated energy fluxes and thickness of the bottom boundary layer. Initially, the accuracy of the model is assessed by performing a detailed comparison of computed tidal elevations and currents in the region, against an extensive database that exists for the M2, S2, N2, K1 and O1 tides. Subsequently, the model is used to compute the tidal energy flux vectors in the region. These show that the major energy flux is confined to the North Channel region, with little energy flux into the Clyde Sea. Comparison with the observed energy flux in the North Channel shows that its across-channel distribution and its magnitude are particularly sensitive to the phase difference between elevation and current. Consequently, small changes in the computed values of these parameters due to slight changes of the order of the uncertainty in the open-boundary values to the model, can significantly influence the computed energy flux. The thickness of the bottom boundary layer in the region is computed using a number of formulations. Depending upon the definition adopted, the empirical coefficient C used to determine its thickness varies over the range 0.1 to 0.3, in good agreement with values found in the literature. In the North Channel, the boundary layer thickness occupies the whole water depth, and hence tidal turbulence produced at the sea bed keeps the region well mixed. In the Clyde Sea, the boundary layer thickness is a small fraction of the depth, and hence the region stratifies.