The Variability of Indonesian Throughflow in Sumba Strait and Its Linkage to the Climate Events
The Variability of Indonesian Throughflow in Sumba Strait and Its Linkage to the Climate Events
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DOI：
10.3844/ajassp.2019.118.133
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发表时间：
2019-04
期刊：
影响因子：
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通讯作者：
A. Bayhaqi;Y. Lenn;D. Surinati;J. Polton;Muhamad Nur;C. Corvianawatie;A. Purwandana
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文献类型：
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作者：
A. Bayhaqi;Y. Lenn;D. Surinati;J. Polton;Muhamad Nur;C. Corvianawatie;A. Purwandana
松巴海峡是印度尼西亚洋流外流通道之一，是太平洋和印度洋水团的交汇点。为了研究流经松巴海峡的ITF的长期变化，本研究使用2016年8月进行的Ekspedisi WIdya Nusantara（EWIN）研究巡航的观测数据，通过参考切变速度来验证高度地转表面流。假定参考层为700米，使用每月等密度/混合层海洋气候（MIMOC）数据计算地转输送。在1993-2016年期间，结果表明，地转变率的季节模式占主导地位。虽然总的地转输送显示出一个主要的向西向印度洋方向，松巴海峡只提供了一小部分（小于0.1西弗）向西ITF地转流。在季节内，最大输送发生在东南季风期间。南爪哇海流（SJC）向东流向萨武海，几乎在每个季风季节都被观测到作为向西ITF的入侵。印度洋的气候模态对松巴海峡表层地转变率的影响可能更大，尽管其年际变化周期不明确。另一方面，太平洋的海气耦合在调节松巴海峡内的地转输送变化方面发挥作用。使用统计方法，研究结果强调，通流可能会受到影响，以及反馈的厄尔尼诺/南方涛动和印度洋OD，因为这些变量的鲁棒性。
As one of the Indonesian Throughflow (ITF) outflow passages, the Sumba Strait is a meeting point for the Pacific and the Indian Ocean water mass. In order to study the long-term variability of ITF flowing via Sumba Strait, this research uses observational data from the Ekspedisi WIdya Nusantara (EWIN) research cruise conducted in August 2016 to validate the altimetric geostrophic surface current by referencing the shear velocity. Stating the referenced level to 700 m, geostrophic transport is calculated using the Monthly Isopycnal/Mixed-Layer Ocean Climatology (MIMOC) data. Over the period of 1993-2016, the results demonstrate a dominant seasonal pattern for the geostrophic variability. While the total geostrophic transport shows a main westward direction towards the Indian Ocean, the Sumba Strait provides only a small portion (less than 0.1 Sv) for westward ITF geostrophic current. Intraseasonally, the maximum transport occurs during the southeast monsoon. The reversal of South Java Current (SJC), which flows with the eastward direction heading to the Savu Sea, is observed as the intrusion for westward ITF in almost every monsoon season. Despite having an unclear year to year cycle, climate mode of the Indian Ocean may have more influence on the surface geostrophic variability at the Sumba Strait. On the other hand, ocean-atmosphere coupling in the Pacific Ocean has a role in regulating geostrophic transport variation within the Sumba Strait. Using a statistical approach, the findings emphasize that the throughflow may well be impacted as well as feedback on both ENSO and IOD since there is robustness in those variables.