Three-dimensional tidal flow in a fjord-like basin with converging width: An analytical model
Three-dimensional tidal flow in a fjord-like basin with converging width: An analytical model
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具有收敛宽度的峡湾状盆地中的三维潮汐流：分析模型
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
A. Valle‐Levinson
中科院分区：
文献类型：
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作者：
Lauren Ross;H. Swart;E. Ensing;A. Valle‐Levinson
采用三维解析模型来了解深而窄（峡湾状）盆地的潮汐动力学。该模型允许盆地的宽度随着离河口的通道距离呈指数衰减。指数收敛数学公式的长度尺度和摩擦参数数学公式（垂直涡流粘度）均为自由参数。模型结果表明，潮幅向盆地头部方向放大。放大取决于通道漏斗状宽度的变窄率和摩擦力。沿槽潮流的跨槽变化对摩擦参数也很敏感。当垂直涡动黏度为强摩擦盆地特征时，或Stokes数大于0.1 （St > 0.1）时，海峡两岸呈典型的顺槽潮流分布。最大的顺水道潮汐速度（根据宽度辐合强度在0.25 ~ 0.5 m s - 1之间）位于盆地中心和表层。Stokes数的减小（St < 0.1）导致沿通道的速度最大值位于靠近横向边界和通道中部的地下。用St的临界值解释了这些潮流分布，并与智利巴塔哥尼亚Reloncavi峡湾的观测结果进行了验证，结果吻合良好。
A three-dimensional analytical model was used to understand tidal dynamics in deep and narrow (fjord-like) basins. This model allows the width of the basin to decay exponentially with along-channel distance from the mouth. Both the length scale of exponential convergence math formula and the friction parameter math formula (vertical eddy viscosity) were the free parameters. Model results show amplification of the tidal amplitude toward the head of the basin. Amplification depends on the narrowing rate of the funnel-like width of the channel and on friction. Cross-channel variations in along-channel tidal flow are also sensitive to the friction parameter. A typical along-channel tidal flow distribution was found across the channel when the vertical eddy viscosity was characteristic of a basin with strong friction, or the Stokes number was larger than 0.1 (St > 0.1). Maximum along-channel tidal velocities (ranging from 0.25 to 0.5 m s−1 depending on width convergence strength) were located in the center of the basin and at the surface. Decreasing values of the Stokes number, St < 0.1, resulted in along-channel velocity maxima located near the lateral boundaries and subsurface in the middle of the channel. These tidal flow distributions were explained by a critical value of St and were verified with observations from Reloncavi Fjord, Chilean Patagonia yielding good agreement.