Climatic Controls on the Interannual Variability of Shelf Circulation in the Northern South China Sea

Deng，Yongfei1; Liu，Zhiqiang1,2; Zu，Tingting2,3; Hu，Jianyu4; Gan，Jianping5; Lin，Yuxin1; Li，Zhibing1; Quan，Qi1,6; Cai，Zhongya7

2022-07-01

10.1029/2022JC018419

JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS   Impact Factor & Quartile

2169-9275

2169-9291

We comprehensively investigate the interannual variability of multi-scale motions in the northern South China Sea (NSCS) and associated influences from the terrestrial, atmospheric, and oceanic processes over the period 1994–2018 based on observations and a numerical simulation. We find that the interannual variabilities of the NSCS circulation and hydrographic properties, in the form of a cross-scale interactive dynamic system, are sensitive to the tropical climate variability represented by the El Niño–Southern Oscillation (ENSO). In coastal areas with less than 30 m depth, the anomalous warm (cold) and less (more) saline waters are regulated by the rate of Pearl River discharge due to the predominant precipitation (evaporation) and positive (negative) heat-flux anomaly in the Pearl River catchment in El Niño (La Niña) years. Controlled by the interannual variabilities of slope current and atmospheric forcings, the shelf current at 30–200 m depth responds asymmetrically to the ENSO, which establishes a stronger northeastward flow anomaly in El Niño years than the southwestward flow anomaly in La Niña years. We further show that the interannual variability of the slope current is jointly governed by the atmospheric and oceanic processes that tend to offset each other in interannual timescales. In particular, the weakened (strengthened) cyclonic wind stress curl over the ocean basin tends to moderate (intensify) the slope current in the NSCS, while this process is mitigated by the stronger (weaker) Kuroshio intrusion in El Niño (La Niña) years.

ENSO interannual variability northern South China Sea shelf current terrestrial forcing

SCI

English

First ; Corresponding

National Natural Science Foundation of China[41906016];National Natural Science Foundation of China[42076026];National Natural Science Foundation of China[91958203];Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[GML2019ZD0210];Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[GML2019ZD0304];Science, Technology and Innovation Commission of Shenzhen Municipality[JCYJ20210324105211031];Science, Technology and Innovation Commission of Shenzhen Municipality[JCYJ20210324105401004];State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences[LTO2006];

WOS:000817905000001

GEOSCIENCES

2-s2.0-85135562642

Scopus

1.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,China
2.Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou),Guangzhou,China
3.State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou,China
4.State Key Laboratory of Marine Environmental Science,College of Ocean and Earth Sciences,Xiamen University,Xiamen,China
5.Department of Ocean Science and Mathematics,Center for Ocean Research in Hong Kong and Macau,Hong Kong University of Science and Technology,Hong Kong
6.State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai,China
7.State Key Laboratory of Internet of Things for Smart City,Department of Civil and Environmental Engineering,University of Macau,Macao

Deng，Yongfei,Liu，Zhiqiang,Zu，Tingting,et al. Climatic Controls on the Interannual Variability of Shelf Circulation in the Northern South China Sea[J]. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS,2022,127(7).

Deng，Yongfei.,Liu，Zhiqiang.,Zu，Tingting.,Hu，Jianyu.,Gan，Jianping.,...&Cai，Zhongya.(2022).Climatic Controls on the Interannual Variability of Shelf Circulation in the Northern South China Sea.JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS,127(7).

Deng，Yongfei,et al."Climatic Controls on the Interannual Variability of Shelf Circulation in the Northern South China Sea".JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 127.7(2022).