Hydrodynamics of spur and groove formations on a coral reef
Hydrodynamics of spur and groove formations on a coral reef
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DOI：
10.1002/jgrc.20225
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发表时间：
2013-06
影响因子：
--
通讯作者：
J. Rogers;S. Monismith;F. Feddersen;C. Storlazzi
中科院分区：
文献类型：
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作者：
J. Rogers;S. Monismith;F. Feddersen;C. Storlazzi
[1]在世界各地的许多珊瑚礁的前礁上发现了刺槽构造。虽然这些地层主要存在于波浪主导的环境中，但它们对波浪驱动的流体动力学的影响尚不清楚。一个二维的，深度平均的，相位分辨的非线性Boussinesq模型（funwaveC）被用来模拟简化的SAG系统上的流体动力学。模拟结果表明，SAG形成与浅化波一起引起近岸拉格朗日环流模式的反旋转循环细胞。驱动模拟流的机制是动量平衡中压力梯度（PG）和非线性波（NLW）项之间的沿岸不平衡。模型参数的变化表明，影响环流的最强因素包括正向波、波高增加、沿岸流弱、正向波高增加和底阻力减小。模拟的环流与基于NLW、PG和底部应力项的动态平衡的简单尺度分析是一致的。模型结果表明，SAG地层有效地驱动循环细胞时，沿岸SAG波长允许衍射的影响，以创建沿岸的波高差异，而不改变平均波角。
[1] Spur and groove (SAG) formations are found on the fore reefs of many coral reefs worldwide. Although these formations are primarily present in wave-dominated environments, their effect on wave-driven hydrodynamics is not well understood. A two-dimensional, depth-averaged, phase-resolving nonlinear Boussinesq model (funwaveC) was used to model hydrodynamics on a simplified SAG system. The modeling results show that the SAG formations together with shoaling waves induce a nearshore Lagrangian circulation pattern of counter-rotating circulation cells. The mechanism driving the modeled flow is an alongshore imbalance between the pressure gradient (PG) and nonlinear wave (NLW) terms in the momentum balance. Variations in model parameters suggest the strongest factors affecting circulation include spur-normal waves, increased wave height, weak alongshore currents, increased spur height, and decreased bottom drag. The modeled circulation is consistent with a simple scaling analysis based on the dynamical balance of NLW, PG, and bottom stress terms. Model results indicate that the SAG formations efficiently drive circulation cells when the alongshore SAG wavelength allows for the effects of diffraction to create alongshore differences in wave height without changing the mean wave angle.