Seasonal variation of eddy shedding from the Kuroshio intrusion in the Luzon Strait

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.

Download Full-text

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

Download Full-text

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.

Download Full-text

Eddy Shedding from the Kuroshio Bend at Luzon Strait

Journal of Oceanography ◽

10.1007/s10872-005-0014-6 ◽

2004 ◽

Vol 60 (6) ◽

pp. 1063-1069 ◽

Cited By ~ 89

Author(s):

Yinglai Jia ◽

Qinyu Liu

Keyword(s):

Luzon Strait ◽

The Kuroshio ◽

Kuroshio Bend ◽

Eddy Shedding

Download Full-text

Influence of island chains on the Kuroshio intrusion in the Luzon Strait

Advances in Atmospheric Sciences ◽

10.1007/s00376-016-6159-y ◽

2017 ◽

Vol 34 (3) ◽

pp. 397-410 ◽

Cited By ~ 6

Author(s):

Zhida Huang ◽

Hailong Liu ◽

Pengfei Lin ◽

Jianyu Hu

Keyword(s):

Luzon Strait ◽

Kuroshio Intrusion ◽

The Kuroshio

Download Full-text

Primary Study of the Mechanism of Eddy Shedding from the Kuroshio Bend in Luzon Strait

Journal of Oceanography ◽

10.1007/s10872-006-0018-x ◽

2005 ◽

Vol 61 (6) ◽

pp. 1017-1027 ◽

Cited By ~ 46

Author(s):

Yinglai Jia ◽

Qinyu Liu ◽

Wei Liu

Keyword(s):

Luzon Strait ◽

Primary Study ◽

The Kuroshio ◽

Kuroshio Bend ◽

Eddy Shedding

Download Full-text

The Seasonal Variation of the Anomalously High Salinity at Subsurface Salinity Maximum in Northern South China Sea from Argo Data

Journal of Marine Science and Engineering ◽

10.3390/jmse9020227 ◽

2021 ◽

Vol 9 (2) ◽

pp. 227

Author(s):

Hui Shen ◽

Li Li ◽

Jianlong Li ◽

Zhiguo He ◽

Yuezhang Xia

Keyword(s):

Seasonal Variation ◽

South China Sea ◽

South China ◽

High Salinity ◽

Sea Water ◽

Northern South China Sea ◽

Kuroshio Intrusion ◽

Argo Data ◽

China Sea ◽

The Kuroshio

The large variations in salinity at the salinity maximum in the northern South China Sea (NSCS), as an indicator for the changes in the Kuroshio intrusion (KI), play an important role in the hydrological cycle. The high salinity here is more than 34.65 at the salinity maximum and is intriguing. In the past, the salinity was difficult to trace in the entire NSCS over long periods due to a lack of high-quality observations. However, due to the availability of accumulated temperature and salinity (T-S) profiles from the Argo program, it is now possible to capture subsurface-maximum data on a large spatiotemporal scale. In this study, the salinity maximum distributed in the subsurface of 80 to 200 m at a density of 23.0–25.5 σθ was extracted from decades of Argo data (on the different pressure surfaces, 2006–2019). We then further studied the spatial distribution and seasonal variation of the salinity maximum and its anomalously high salinity. The results suggest that a high salinity (salinity > 34.65, most of which is located at the shallow depths < 100 m) at the subsurface salinity-maximum layer often occurs in the NSCS, especially near the Luzon Strait, which accounts for about 23% of the total salinity maximum. In winter, the anomalously high salinity at the shallow subsurface salinity maximum can extend to the south of 17° N, while it rarely reaches 18° N and tends to locate at deeper waters in summer. The T-S values of the anomalously high-salinity water are between the mean T-S values in the NSCS and north Pacific subsurface water, implying that the outer sea water gradually mixes with the South China Sea water after passing through the Luzon Strait. Finally, our results show that the factors play an important role in the appearance and distribution of the anomalously high salinity at the subsurface salinity maximum, including the strength of the Kuroshio intrusion, the local wind stress curl and the anticyclonic eddy shedding from the loop current.

Download Full-text