Interaction between internal solitary waves and an isolated atoll in the Northern South China Sea
Interaction between internal solitary waves and an isolated atoll in the Northern South China Sea
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DOI：
10.1007/s10236-010-0323-1
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发表时间：
2010-07
期刊：
影响因子：
2.3
通讯作者：
Guan-Yu Chen;R. Wu;Yu-Hwui Wang
中科院分区：
文献类型：
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作者：
Guan-Yu Chen;R. Wu;Yu-Hwui Wang
东沙环礁的温度下降具有明显的日变化周期，并被认为是内孤立波（ISW）的结果。冷水事件每天发生，持续几个小时，时间尺度比ISW长得多。为了进一步了解这一物理过程，本文利用普林斯顿海洋模式对东沙环礁与ISW的相互作用进行了详细的数值模拟。内孤立波被发现合并，成为不对称的，并在浅滩化过程中打破。然后，一股猛烈的涌潮形成，像一个团一样沿着斜坡向上流动，把冰冷的深水带到浅滩。11月的温度变化和流场模拟结果与实测的最大温降非常相似，其中流场主要由ISW控制。在合并过程中，三个ISW成为一个较长的波，延长了冷却过程的时间尺度相比，一个ISW。环礁周围的台阶也大大增加了当地生态系统暴露在寒冷深水中的时间。在没有该步骤的情况下，相同的计算产生了更短的冷水循环时间。
Substantial temperature drops in the Dongsha Atoll with diurnal period have been reported and considered to be the result of an internal solitary wave (ISW). The cold water event occurs daily with duration of a few hours, a time scale much longer than that of the ISW. To further understand the physical process, a detailed numerical simulation on the interaction of the Dongsha Atoll and the ISW is carried out using the Princeton Ocean Model. Internal solitary waves are found to merge, become asymmetric, and break in the shoaling process. Then, a violent tidal bore forms and runs up the slope as a bolus, bringing up cold deep water to the shallows. The simulated temperature variation and flow field in November are very similar to the largest temperature drop in the field measurement where the flow field is dominated by the ISW. In the merging process, three ISWs become one longer wave lengthening the time scale of the cooling process compared with that of a single ISW. The step around the atoll also contributes substantially by increasing the exposure time of the local ecosystem to the cold deep water. The same calculation in the absence of the step yields a much shorter time for the cold water cycle.