Institutional Repository of Key Laboratory of Ocean Circulation and Wave Studies, Institute of Oceanology, Chinese Academy of Sciences
| The Northeast-Southwest Oscillating Equatorial Mode of the Tropical Instability Wave and Its Impact on Equatorial Mixing | |
Liu, Chuanyu1,2,3,4; Wang, Xiaowei1,2,3,4; Koehl, Armin5; Wang, Fan1,2,3,4 ; Liu, Zhiyu6,7
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| 2019-01-16 | |
| 发表期刊 | GEOPHYSICAL RESEARCH LETTERS
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| ISSN | 0094-8276 |
| 卷号 | 46期号:1页码:218-225 |
| 通讯作者 | Liu, Chuanyu(chuanyu.liu@qdio.ac.cn) ; Wang, Xiaowei(wangxiaowei@qdio.ac.cn) |
| 摘要 | The tropical instability waves (TIWs) in the eastern Pacific consist of waves with central periods of about 33 and 17days. While the former manifest as vortices north of the equator, and are known to modulate diapycnal mixing at their southern edge, the latter remain largely unexplored. Here the structure of the 17-day TIWs and the mechanism through which they may influence equatorial mixing are investigated based on long term in situ measurements and reanalysis data. Different from the well-recognized meridional velocity oscillation, the 17-day TIWs are found to induce northeast-southwest (NE-SW) velocity oscillations. They are confined within but asymmetric about the equator, differing from free Yanai waves, which they were commonly assumed to resemble. The vertical shear associated with the westward anomalous velocity superimposes on the shear of the mean flow, resulting in the strongest shear in the upper thermocline that is expected to facilitate diapycnal mixing therein. Plain Language Summary Observed from satellites, the tropical instability wave (TIW) in the eastern tropical Pacific Ocean is a 1,000-km-long gigantic combination of waves and vortexes. It emerges between the energetic zonally interleaving equatorial currents, impacts the atmosphere, and transfers enormous energy to the western Pacific Ocean and to the deep ocean as wellone of the research foci for both physical oceanographers and meteorologists. However, the structures of its huge body, and the associated complicated smaller-scale processes, remain unrevealed, primarily because the measurements that have been conducted, usually by research vessels, are too limited to derive a full picture. Here based on long-term observations at a hotspot of TIW and 4-D numerical model outputs, we identify the structure of TIW at the equator, which manifests as a pair of slanted clockwise and anticlockwise vortexes, and induces strong east-west oscillations. We also find the most efficient mechanism for the TIW to strengthen vertical velocity shear, shear instability, and ocean turbulent mixing. The findings therefore are important for understanding the TIW dynamics, TIWs' signatures in atmosphere-ocean interactions, and their impact on vertical heat transport from warmer sea surface to colder subsurface layers of the ocean. |
| 关键词 | tropical instability wave TIW instability equatorial mixing vertical mixing pacific cold tongue |
| DOI | 10.1029/2018GL080226 |
| 收录类别 | SCI |
| 语种 | 英语 |
| 资助项目 | Strategic Priority Research Program of CAS[XDA19060102] ; Strategic Priority Research Program of CAS[QYZDB-SSW-DQC030] ; Key Research Program of Frontier Sciences of CAS[XDA19060102] ; Key Research Program of Frontier Sciences of CAS[QYZDB-SSW-DQC030] ; National Natural Science Foundation of China[41606026] ; National Natural Science Foundation of China[41730534] ; National Natural Science Foundation of China[41622601] ; National Natural Science Foundation of China[91858201] ; National Natural Science Foundation of China[Y72143101B] ; Aoshan Talents Program by the QNML[2017ASTCP-ES03] ; Aoshan Talents Program by the QNML[2015ASTP] ; Strategic Priority Research Program of CAS[XDA19060102] ; Strategic Priority Research Program of CAS[QYZDB-SSW-DQC030] ; Key Research Program of Frontier Sciences of CAS[XDA19060102] ; Key Research Program of Frontier Sciences of CAS[QYZDB-SSW-DQC030] ; National Natural Science Foundation of China[41606026] ; National Natural Science Foundation of China[41730534] ; National Natural Science Foundation of China[41622601] ; National Natural Science Foundation of China[91858201] ; National Natural Science Foundation of China[Y72143101B] ; Aoshan Talents Program by the QNML[2017ASTCP-ES03] ; Aoshan Talents Program by the QNML[2015ASTP] |
| WOS研究方向 | Geology |
| WOS类目 | Geosciences, Multidisciplinary |
| WOS记录号 | WOS:000456938600024 |
| 出版者 | AMER GEOPHYSICAL UNION |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.qdio.ac.cn/handle/337002/160636 |
| 专题 | 海洋环流与波动重点实验室 |
| 通讯作者 | Liu, Chuanyu; Wang, Xiaowei |
| 作者单位 | 1.Chinese Acad Sci, Inst Oceanol, Key Lab Ocean Circulat & Waves, Qingdao, Peoples R China 2.Pilot Natl Lab Marine Sci & Technol Qingdao QNLM, Marine Dynam Proc & Climate Funct Lab, Qingdao, Peoples R China 3.Univ Chinese Acad Sci, Beijing, Peoples R China 4.Chinese Acad Sci, Ctr Ocean Mega Sci, Qingdao, Peoples R China 5.Univ Hamburg, Inst Oceanog, Hamburg, Germany 6.Xiamen Univ, Coll Ocean & Earth Sci, State Key Lab Marine Environm Sci, Xiamen, Peoples R China 7.Xiamen Univ, Dept Phys Oceanog, Coll Ocean & Earth Sci, Xiamen, Peoples R China |
| 第一作者单位 | 海洋环流与波动重点实验室 |
| 通讯作者单位 | 海洋环流与波动重点实验室 |
| 推荐引用方式 GB/T 7714 | Liu, Chuanyu,Wang, Xiaowei,Koehl, Armin,et al. The Northeast-Southwest Oscillating Equatorial Mode of the Tropical Instability Wave and Its Impact on Equatorial Mixing[J]. GEOPHYSICAL RESEARCH LETTERS,2019,46(1):218-225. |
| APA | Liu, Chuanyu,Wang, Xiaowei,Koehl, Armin,Wang, Fan,&Liu, Zhiyu.(2019).The Northeast-Southwest Oscillating Equatorial Mode of the Tropical Instability Wave and Its Impact on Equatorial Mixing.GEOPHYSICAL RESEARCH LETTERS,46(1),218-225. |
| MLA | Liu, Chuanyu,et al."The Northeast-Southwest Oscillating Equatorial Mode of the Tropical Instability Wave and Its Impact on Equatorial Mixing".GEOPHYSICAL RESEARCH LETTERS 46.1(2019):218-225. |
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