Influence of the Kuroshio Intrusion on Deep Flow Intraseasonal Variability in the Northern South China Sea

Quan, Qi1; Liu, Zhiqiang1; Sun, Shantong2; Cai, Zhongya3,4,5; Yang, Yang6; Jin, Guangzhen7; Li, Zhibing1; Liang, X. San6

2021-07-01

10.1029/2021JC017429

JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS   影响因子和分区

2169-9275

2169-9291

Interactions between the open ocean and marginal seas have been suggested to be critical to the redistribution and dissipation of global energy. Here, we propose a mechanism for the upper open ocean influencing the deep flow in marginal seas that hinges on the formation and propagation of topographic Rossby waves (TRWs). Observations and high-resolution simulations suggest substantial intraseasonal variability with periods of 5-60 days associated with the deep flow over continental slopes of the northern South China Sea (NSCS). These fluctuations generally account for over 40% of the total deep kinetic energy variability and the number can reach 70% over the slopes to the west of the Luzon Strait, southwest of the Dongsha Islands, and northeast of the Xisha Islands. By examining the spatiotemporal features of the fluctuations, we demonstrate that the intraseasonal variability of the deep flow in the NSCS is closely associated with TRWs. Using a recently developed multiscale energetics analysis in combination with a ray tracing model, we show that the energy sources of TRWs can be traced back to the east of the Dongsha Islands, where the Kuroshio intrusion and related eddies energize the TRWs primarily through pressure work. These waves propagate westward across the NSCS and drive the intraseasonal variability of the deep flow over continental slopes. Our findings highlight an energy pathway from the open ocean western boundary current to the abyssal marginal sea that could modulate regional circulation as well as exchanges between major ocean basins.

South China Sea Kuroshio topographic Rossby wave energy eddy deep flow

SCI

英语

第一 ; 通讯

National Natural Science Foundation of China[42006007,41906016,42006009,41806023,41975064] ; China Postdoctoral Science Foundation["2020M682767","2020M681269"] ; Science and Technology Development Fund, Macau SAR[SKL-IOTSC-2021-2023] ; Natural Science Foundation of Guangdong Province[2019A1515011487] ; Fundamental Research Funds for the Central Universities[20184200031610059]

Oceanography

Oceanography

WOS:000681412200019

AMER GEOPHYSICAL UNION

GEOSCIENCES

Web of Science

1.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen, Peoples R China
2.CALTECH, Environm Sci & Engn, Pasadena, CA USA
3.Univ Macau, State Key Lab Internet Things Smart City, Macau, Peoples R China
4.Univ Macau, Dept Civil & Environm Engn, Macau, Peoples R China
5.Ctr Ocean Res Hongkong & Macau, Macau, Peoples R China
6.Nanjing Univ Informat Sci & Technol, Sch Marine Sci, Nanjing, Peoples R China
7.Shanghai Ocean Univ, Coll Marine Ecol & Environm, Shanghai, Peoples R China

Quan, Qi,Liu, Zhiqiang,Sun, Shantong,et al. Influence of the Kuroshio Intrusion on Deep Flow Intraseasonal Variability in the Northern South China Sea[J]. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS,2021,126(7).

Quan, Qi.,Liu, Zhiqiang.,Sun, Shantong.,Cai, Zhongya.,Yang, Yang.,...&Liang, X. San.(2021).Influence of the Kuroshio Intrusion on Deep Flow Intraseasonal Variability in the Northern South China Sea.JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS,126(7).

Quan, Qi,et al."Influence of the Kuroshio Intrusion on Deep Flow Intraseasonal Variability in the Northern South China Sea".JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 126.7(2021).