Impacts of the Kuroshio Intrusion through the Luzon Strait on the Local Precipitation Anomaly

The Kuroshio Current has its origin in the northwestern Pacific, flowing northward to the east of Taiwan and the northern part of Luzon Island. As the Kuroshio Current flows northward, it quasi-periodically intrudes (hereafter referred to as Kuroshio intrusion (KI)) into the northern South China Sea (SCS) basin through the Luzon Strait. Despite the complex generation mechanisms of KI, the purpose of this study is to improve our understanding of the effects of KI through the Luzon Strait on the regional atmospheric and weather variations. Long-term multiple satellite observations, including absolute dynamic topography, absolute geostrophic currents, sea surface winds by ASCAT, multi-scale ultra-high resolution sea surface temperature (MURSST) level-four analysis, and research-quality three-hourly TRMM multi-satellite precipitation analysis (TMPA), was used to systematically examine the aforementioned scientific problem. Analysis indicates that the KI is interlinked with the consequential anomalous precipitation off southwestern Taiwan. This anomalous precipitation would lead to ~560 million tons of freshwater influx during each KI event. Subsequently, independent moisture budget analysis suggests that moisture, mainly from vertical advection, is the possible source of the precipitation anomaly. Additionally, a bulk formula analysis was applied to understand how KI can trigger the precipitation anomaly through vertical advection of moisture without causing an evident change in the low-level flows. These new research findings might reconcile the divisiveness on why winds are not showing a synchronous response during the KI and consequential anomalous precipitation events.

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Holocene sea surface temperature and salinity variation in the northern South China Sea as modulated by the Kuroshio Current intrusion

Journal of Earth Science & Climatic Change ◽

10.4172/2157-7617.c1.025 ◽

2016 ◽

Vol 07 (05) ◽

Author(s):

Shuhuan Du

Keyword(s):

South China Sea ◽

Surface Temperature ◽

Sea Surface Temperature ◽

South China ◽

Northern South China Sea ◽

Kuroshio Current ◽

Sea Surface ◽

Salinity Variation ◽

China Sea ◽

The Kuroshio

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Impacts of the Kuroshio intrusion entering the Luzon Strait on the local atmosphere by satellite observations

Remote Sensing of the Atmosphere, Clouds, and Precipitation VII ◽

10.1117/12.2324044 ◽

2018 ◽

Author(s):

Zhe-Wen Zheng ◽

Min-Chuan Weng ◽

Wen-Pin Fang

Keyword(s):

Luzon Strait ◽

Satellite Observations ◽

Kuroshio Intrusion ◽

The Kuroshio

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Late Quaternary course changes of the Kuroshio Current in the Ryukyu Arc region, northwestern Pacific Ocean

Marine Micropaleontology ◽

10.1016/s0377-8398(99)00010-9 ◽

1999 ◽

Vol 37 (1) ◽

pp. 23-40 ◽

Cited By ~ 148

Author(s):

Hiroshi Ujiié ◽

Yurika Ujiié

Keyword(s):

Pacific Ocean ◽

Late Quaternary ◽

Kuroshio Current ◽

Northwestern Pacific ◽

Northwestern Pacific Ocean ◽

Ryukyu Arc ◽

Course Changes ◽

The Kuroshio

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Analysis of longer period variation of the Kuroshio Current intrusion into the Luzon Strait using rectified wavelet power spectra

Progress In Oceanography ◽

10.1016/j.pocean.2017.04.013 ◽

2017 ◽

Vol 156 ◽

pp. 61-77 ◽

Cited By ~ 2

Author(s):

Yaochu Yuan ◽

Chenghao Yang ◽

Yu-heng Tseng ◽

Xiao-Hua Zhu ◽

Huiqun Wang ◽

...

Keyword(s):

Power Spectra ◽

Kuroshio Current ◽

Luzon Strait ◽

Period Variation ◽

The Kuroshio

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Weakening of the Kuroshio Intrusion into the South China Sea over the Past Two Decades

Journal of Climate ◽

10.1175/jcli-d-12-00315.1 ◽

2013 ◽

Vol 26 (20) ◽

pp. 8097-8110 ◽

Cited By ~ 39

Author(s):

Feng Nan ◽

Huijie Xue ◽

Fei Chai ◽

Dongxiao Wang ◽

Fei Yu ◽

...

Keyword(s):

South China Sea ◽

South China ◽

Luzon Strait ◽

The South China Sea ◽

Negative Trend ◽

Kuroshio Intrusion ◽

The South ◽

China Sea ◽

The Past ◽

The Kuroshio

Abstract Inferred from the satellite and in situ hydrographic data from the 1990s and 2000s, the Kuroshio intrusion into the South China Sea (SCS) had a weakening trend over the past two decades. Associated with the weakened Kuroshio intrusion, the Kuroshio loop and eddy activity southwest of Taiwan became weaker, whereas the water above the salinity minimum became less saline in the northern SCS. The sea surface height southwest of Taiwan increased at a slower rate compared to other regions of the SCS because of the weakened Kuroshio intrusion. Simulations using the Regional Ocean Modeling System (ROMS) Pacific model show that the strength of the Kuroshio intrusion into the SCS decreased from 1993 to 2010 with a negative trend, −0.24 sverdrups (Sv) yr−1 (1 Sv ≡ 106 m3 s−1), in the total Luzon Strait transport (LST). Although wind-induced Ekman transport through the Luzon Strait became weaker, the magnitude at 0.001 Sv yr−1 was too small to compensate for the negative trend of the LST. On the other hand, the piling up of the water induced by monsoon winds was an important mechanism for changing the pressure gradient across the Luzon Strait and eventually affecting the LST. The sea level gradient between the western Pacific and the SCS had a negative trend, −0.10 cm yr−1, corresponding to a negative trend in the geostrophic transport at −0.20 Sv yr−1. The Kuroshio transport east of Luzon Island also had a negative trend, which might also be linked to the weakening Kuroshio intrusion.

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A Strong Kuroshio Intrusion into the South China Sea and Its Accompanying Cold-Core Anticyclonic Eddy in Winter 2020–2021

Remote Sensing ◽

10.3390/rs13142645 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2645

Author(s):

Zhenyu Sun ◽

Jianyu Hu ◽

Zhaozhang Chen ◽

Jia Zhu ◽

Longqi Yang ◽

...

Keyword(s):

Kuroshio Current ◽

Anticyclonic Eddy ◽

Ekman Transport ◽

Maximum Diameter ◽

Current Loop ◽

Coastal Current ◽

Kuroshio Intrusion ◽

Wind Stress Curl ◽

The Kuroshio ◽

Cold Core

Multiple remote sensing datasets, combined with in-situ drifter observations, were used to analyze the Kuroshio intrusion through the Luzon Strait (LS). The results showed that a strong Kuroshio Current Loop (KCL) and accompanying anticyclonic eddy (ACE) existed in winter 2020–2021. As quantitatively demonstrated by the Double Index (DI), the Kuroshio Warm Eddy Index (KWI) had low values during a long sustained period compared to those in all other years in the available historical records. Remarkable kinematic properties (i.e., amplitude, diameter, propagated distance, lifespan and propagating speed) of the accompanying ACE were extracted by automatic eddy detection algorithms, showing that the ACE had a maximum diameter of 381 km and a peak amplitude of 50 cm, which significantly exceeded the previous statistics in winter. The orographic negative wind stress curl southwest of Taiwan Island and the westward Ekman transport through the LS during the winter half year of 2020–2021 both had large values beyond their historical maxima. Hence wind forcing is regarded as the primary forcing mechanism during this event. Alternating cyclonic eddies (CEs) and ACEs approaching on the east of the LS were identified, indicating that the interaction between the Kuroshio and the impinging CEs at proper locations made extra contributions to enhancing the KCL. The accompanying ACE had a distinctive feature of a cold-core structure at the surface layer, so as to be categorized as a cold core ACE (CC-ACE), and the temperature difference between the cold core and outer warm ring was maintained for three months. The generation and long duration of the CC-ACE may be due to the sustaining entrainment supported by the warm water from Kuroshio intrusion and the Northwest Luzon Coastal Current (NWLCC) successively.

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Biogeographic Role of the Kuroshio Current Intrusion in the Microzooplankton Community in the Boundary Zone of the Northern South China Sea

Microorganisms ◽

10.3390/microorganisms9051104 ◽

2021 ◽

Vol 9 (5) ◽

pp. 1104

Author(s):

Ping Sun ◽

Silu Zhang ◽

Ying Wang ◽

Bangqin Huang

Keyword(s):

South China Sea ◽

South China ◽

Northern South China Sea ◽

Kuroshio Current ◽

Equation Modeling ◽

Rrna Gene ◽

Kuroshio Intrusion ◽

China Sea ◽

Ciliate Community ◽

The Kuroshio

Kuroshio Current intrusion (KCI) has significant impacts on the oceanographic conditions and ecological processes of the Pacific-Asian marginal seas. Little is known to which extent and how, specifically, the microzooplankton community can be influenced through the intrusion. Here, we focused on ciliates that often dominated the microzooplankton community and investigated their communities using high-throughput sequencing of 18S rRNA gene transcripts in the northern South China Sea (NSCS), where the Kuroshio Current (KC) intrudes frequently. We first applied an isopycnal mixing model to assess the fractional contribution of the KC to the NSCS. The ciliate community presented a provincial distribution pattern corresponding to more and less Kuroshio-influenced stations. Structural equation modeling revealed a significant impact of the KCI on the community, while environmental variables had a marginal impact. KCI-sensitive OTUs were taxonomically diverse but mainly belonged to classes Spirotrichea and Phyllopharyngea, suggesting the existence of core ciliates responding to the KCI. KCI-sensitive OTUs were grouped into two network modules that showed contrasting abundance behavior with the KC fraction gradient, reflecting differential niches (i.e., winner and loser) in the ciliate community during the Kuroshio intrusion scenarios. Our study showed that the Kuroshio intrusion, rather than environmental control, was particularly detrimental to the oligotrophic microzooplankton community.

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Biomarkers in the rock outcrop of the Kazusa Group reveal palaeoenvironments of the Kuroshio region

Communications Earth & Environment ◽

10.1038/s43247-021-00154-2 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Hiroto Kajita ◽

Ayumi Maeda ◽

Masayuki Utsunomiya ◽

Toshihiro Yoshimura ◽

Naohiko Ohkouchi ◽

...

Keyword(s):

Sediment Cores ◽

Kuroshio Current ◽

Sea Surface ◽

Average Chain Length ◽

Rock Outcrop ◽

Diagenetic Alteration ◽

Organic Biomarkers ◽

The Kuroshio ◽

Kuroshio Region ◽

Long Chain

AbstractLong-chain alkenones and n-alkanes preserved in marine and lake sediment cores are widely used to reconstruct palaeoenvironments. However, applying this technique to exposed sedimentary rock sequences is relatively challenging due to the potential for the diagenetic alteration of organic biomarkers. Here, we extract long-chain alkenones and n-alkanes from an exposed outcrop of the Kazusa Group in central Japan, one of the most continuous sedimentary successions in the world, covering almost the entire Pleistocene. We find that the alkenone unsaturation ratio and average chain length of n-alkanes appears to reflect the glacial-interglacial changes in sea surface temperature and terrestrial climate, respectively. Alkenone-based sea surface temperatures between 1.1 and 1.0 million years ago concur with foraminiferal Mg/Ca-based temperature estimates and may reflect an intrusion of the Kuroshio Current. We suggest that the preservation of these biomarkers in the Kazusa Group demonstrates its potential to provide a detailed palaeoenvironmental record.

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