Internal Solitary Waves in the Andaman Sea Revealed by Long-term Mooring Observations
Internal Solitary Waves in the Andaman Sea Revealed by Long-term Mooring Observations
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DOI：
10.1175/jpo-d-20-0310.1
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发表时间：
2021-10
影响因子：
3.5
通讯作者：
Yunchao Yang;Xiaodong Huang;Wei Zhao;Chun Zhou;Siwei Huang;Zhiwei Zhang;Jiwei Tian
中科院分区：
文献类型：
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作者：
Yunchao Yang;Xiaodong Huang;Wei Zhao;Chun Zhou;Siwei Huang;Zhiwei Zhang;Jiwei Tian
利用两个系泊系统近22个月的观测资料，揭示了安达曼海内孤立波的复杂行为。从苏门答腊岛西北部和Car Nicobar南部的海底山脊发出，两种类型的ISW，被称为S-和C-ISW，分别在测量中被确定，和S-ISW被发现一般比C-ISW更强。观察到的S-和C-ISW经常出现多波包，分别占其观察到的事件的87%和43%。两个系泊站同时采集的数据显示，沿沿着S-ISW波峰的波动性明显，北方部分的平均波幅比南方部分大36%。对到达时间的分析表明，北方部分的S-ISW比南方部分的S-ISW发生更频繁，到达更不规则。此外，ISW的时间变化在月和季节时间尺度上存在显著差异，春季和秋季的S-ISW相对较强。在年际时间尺度上，ISW的时间变化一般是微妙的。层结的变化主要受季风、赤道印度洋风场和安达曼海中尺度涡旋的影响，而层结的变化主要受层结的影响。通过对长期观测数据的分析，我们认为，观测到的ISW可能是通过潮汐释放机制产生的，其产生过程明显受背景环流的调制。
The complex behaviors of internal solitary waves (ISWs) in the Andaman Sea were revealed using data collected over nearly 22-month-long observation period completed by two moorings. Emanating from the submarine ridges northwest of Sumatra Island and south of Car Nicobar, two types of ISWs, referred to as S- and C-ISWs, respectively, were identified in the measurements, and S-ISWs were generally found to be stronger than C-ISWs. The observed S- and C-ISWs frequently appeared as multi-wave packets, accounting for 87% and 43% of their observed episodes, respectively. The simultaneous measurements collected by the two moorings featured evident variability along the S-ISW crests, with the average wave amplitude in the northern portion being 36% larger than that in the southern portion. The analyses of the arrival times revealed that the S-ISWs in the northern portion occurred more frequently and arrived more irregularly than those in the southern portion. Moreover, the temporal variability of ISWs drastically differed on monthly and seasonal time scales, characterized by relatively stronger S-ISWs in spring and autumn. Over interannual time scale, the temporal variations in ISWs were generally subtle. The monthly-to-annual variations of ISWs could be mostly explained by the variability in stratification, which could be modulated by the monsoons, the winds in equatorial Indian Ocean and the mesoscale eddies in Andaman Sea. From careful analyses preformed based on the long-term measurements, we argued that the observed ISWs were likely generated via internal tide release mechanism and their generation processes were obviously modulated by background circulations.