Abstract
Altimeter data and output from the HYbrid Coordinate Ocean Model global assimilation run are used to study the seasonal variation of eddy shedding from the Kuroshio intrusion in the Luzon Strait. The results suggest that most eddy shedding events occur from December through March, and no eddy shedding event occurs in June, September, or October. About a month before eddy shedding, the Kuroshio intrusion extends into the South China Sea and a closed anticyclonic eddy appears inside the Kuroshio loop which then detaches from the Kuroshio intrusion. Anticyclonic eddies detached from December through February move westward at a speed of about 0.1 m s−1 after shedding, whereas eddies detached in other months either stay at the place of origin or move westward at a very slow speed (less than 0.06 m s−1). The HYCOM outputs and QuikSCAT wind data clearly show that the seasonal variation of eddy shedding is influenced by the monsoon winds. A comparison between eddy volume and integrated Ekman transport indicates that, once the integrated Ekman transport exceeds 2 × 1012 m3 (which roughly corresponds to the volume of an eddy), the Kuroshio intrusion expands and an eddy shedding event occurs within 1 month. We infer that the Ekman drift of the northeasterly monsoon pushes the Kuroshio intrusion into the SCS, creates a net westward transport into the Strait, and leads to an eddy detachment from the Kuroshio.
This is a preview of subscription content, access via your institution.








References
AVISO (2006) SSALTO/DUACS user handbook: (M)SLA and (M)ADT near-real time and delayed time products. Archiving, Validation and Interpretation of Satellite Oceanographic Data (AVISO), Ramonville St-Agne, France
Cai S, Long X, Wu R, Wang S (2008) Geographical and monthly variability of the first baroclinic Rossby radius of deformation in the South China Sea. J Mar Sys 74:711–720. doi:https://doi.org/10.1016/j.jmarsys.2007.12.008
Chassignet EP, Hurlburt HE, Metzger EJ, Smedstad OM, Cummings J, Halliwell GR, Bleck R, Baraille R, Wallcraft AJ, Lozano C, Tolman HL, Srinivasan A, Hankin S, Cornillon P, Weisberg R, Barth A, He R, Werner F, Wilkin J (2009) U.S. GODAE: Global Ocean Prediction with the HYbrid Coordinate Ocean Model (HYCOM). Oceanography 22:64–75
Farris A, Wimbush M (1996) Wind-induced Kuroshio intrusion into the South China Sea. J Oceanogr 52:771–784
Jia Y, Liu Q (2004) Eddy shedding from the Kuroshio bend at Luzon Strait. J Oceanogr 60:1063–1069
Jia Y, Liu Q, Liu W (2005) Primary study of the mechanism of eddy shedding from the Kuroshio bend in Luzon Strait. J Oceanogr 61:1017–1027
Liang W, Yang Y, Tang T, Chuang W (2008) Kuroshio in the Luzon Strait. J Geophys Res 113:C08048. doi:https://doi.org/10.1029/2007JC004609
Maximenko NA, PP Niiler (2005) Hybrid decade-mean global sea level with mesoscale resolution. In: N. Saxena (ed) Recent advances in marine science and technology. PACON International, Honolulu, pp 55–59
Metzger EJ, Hurlburt HE (1996) Coupled dynamics of the South China Sea, the Sulu Sea and the Pacific Ocean. J Geophys Res 101:12331–12352
Metzger EJ, Hurlburt HE (2001) The nondeternimistic nature of Kuroshio penetration and eddy shedding in the South China Sea. J Phys Oceanogr 31:1712–1732
Nof D (2005) The momentum imbalance paradox revisited. J Phys Oceanogr 35:1928–1939
Nof D, Jia Y, Chassignet E, Bozec A (2011) Fast wind-induced migration of Leddies in the South China Sea. J Phys Oceanogr. doi:https://doi.org/10.1175/2011JPO4530.1 (in press)
Perry KL (2001) SeaWinds on QuikSCAT Level 3 Daily, Gridded Ocean Wind Vectors (JPL SeaWinds Project). Version 1.1, JPL Document D-20335. Jet Propulsion Laboratory, Pasadena
Qu T, Mitsudera H, Yamagata T (2000) Intrusion of the North Pacific waters into the South China Sea. J Geophys Res 105:6415–6424
Rio MH, Schaeffer P, Moreaux G, Lemoine JM, Bronner E (2009) A new mean dynamic topography computed over the global ocean from GRACE data, altimetry and in situ measurements. Poster communication at OceanObs09 symposium, 21–25 September 2009, Venice. Available on https://doi.org/www.aviso.oceanobs.com/fileadmin/documents/data/products/ auxiliary/MDT_Cnes-CLS09_poster_Oceanobs09.pdf
Semtner J Jr, Chervin R (1992) Ocean circulation from a global eddy-resolving model. J Geophys Res 97:5493–5550
Shaw PT (1991) The seasonal variation of the intrusion of the Philippine Sea water into the South China Sea. J Geophys Res 96:821–827
Sheremet VA (2001) Hysteresis of a western boundary current leaping across a gap. J Phys Oceanogr 31:1247–1259
Sheu W, Wu C, Oey L (2010) Blocking and Westward Passage of Eddies in the Luzon Strait. Deep-Sea Res II 57:1783–1791. doi:https://doi.org/10.1016/j.dsr2.2010.04.004
Wang D, Xu H, Lin J, Hu J (2008) Anticyclonic eddies in the northeastern South China Sea during winter 2003/2004. J Oceanogr 64:925–935. doi:https://doi.org/10.1007/s10872-008-0076-3
Yuan D, Han W, Hu D (2006) Surface Kuroshio path in the Luzon Strait area derived from satellite remote sensing data. J Geophys Res 111:C11007. doi:https://doi.org/10.1029/2005JC003412
Yuan D, Han W, Hu D (2007) Anti-cyclonic eddies northwest of Luzon in summer-fall observed by satellite altimeters. Geophys Res Lett 34:L13610. doi:https://doi.org/10.1029/2007GL029401
Zhao W, Hou Y, Qi P, Ken-tang LE, Li MK (2009) The effects of monsoons and connectivity of South China Sea on the seasonal variations of water exchange in the Luzon Strait. J Hydrodyn 21:264–270
Acknowledgments
The authors thank the two anonymous reviewers for valuable comments and detailed suggestions to improve the manuscript. We thank Kathy Fearon for help with the English writing. The altimeter data are obtained from the Aviso Web site at https://doi.org/www.aviso.oceanobs.com/en/data/index.html. Y. Jia is supported by Chinese National Key Basic Research Program (2007CB411803) and National Natural Science Foundation of China (40706005). E.P. Chassignet acknowledges the support of NSF grant OCE-0752225.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jia, Y., Chassignet, E.P. Seasonal variation of eddy shedding from the Kuroshio intrusion in the Luzon Strait. J Oceanogr 67, 601–611 (2011). https://doi.org/10.1007/s10872-011-0060-1
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10872-011-0060-1
Keywords
- Eddy shedding
- Kuroshio intrusion
- Luzon Strait
- Seasonal variation