Ocean Dynamics

, Volume 62, Issue 8, pp 1187–1194 | Cite as

Variability analysis of Kuroshio intrusion through Luzon Strait using growing hierarchical self-organizing map

  • I-Fong Tsui
  • Chau-Ron WuEmail author


An advanced artificial neural network classification algorithm is applied to 18 years of gridded mean geostrophic velocity multi-satellite data to study the Kuroshio intrusion into the South China Sea through the Luzon Strait. The results suggest that the Kuroshio intrusion may occur year round. However, intrusion is not the major characteristic of the region. The intrusion mode occurs only 25.8 % of the time. Winter intrusion events are more frequent than summer events. Both stronger intrusion (which is related to wind speed) and weaker intrusion (which may be related to the upstream Kuroshio transport) may occur during winter, but stronger intrusion is dominant. In summer, the Kuroshio intrusion is almost the weaker type. The Kuroshio intrusion through the Luzon Strait usually occurs when the Pacific decadal oscillation index is positive (72.1 % of the time). This study shows that growing hierarchical self-organizing map is a useful tool for analyzing Kuroshio intrusion through the Luzon Strait.


Luzon strait Kuroshio intrusion Growing hierarchical self-organizing map (GHSOM) Pacific decadal oscillation (PDO) 



The authors would like to thank the two anonymous reviewers for their careful review of the manuscript and detailed suggestions to improve the manuscript. This research was supported by the National Science Council, Taiwan, Republic of China, under grants NSC 100-2628-M-003-001.


  1. Andres M, Park JH, Wimbush M, Zhu XH, Nakamura H, Kim K, Chang KI (2009) Manifestation of the Pacific Decasal Oscillstion in the Kuroshio. Geophys Res Lett 36:L16602. doi: 10.1029/2009GL039216 CrossRefGoogle Scholar
  2. Caruso M, gawarkiewicz G, and Bearsley RC (2006) Interannual variability of the Kuroshio intrusion in the South China Sea. J Oceanogr 62:559–575CrossRefGoogle Scholar
  3. Ceballos LI, Lorenzo ED, Hoyos CD, Schneider N, Taguchi B (2009) North pacific gyre oscillation synchronizes climate fluctuations in the eastern and western boundary system. J Clim 22:5163–5174CrossRefGoogle Scholar
  4. Centurioni LR, Niiler PP, Lee DK (2004) Observation of inflow of Philippine Sea surface water into the South China Sea through the Luzon Strait. J Phys Oceanogr 34:113–121CrossRefGoogle Scholar
  5. Farris A, Wimbush M (1996) Wind-induced intrusion into the South China Sea. J Oceanogr 52:771–784CrossRefGoogle Scholar
  6. Hsin YC, Wu CR, Shaw PT (2008) Spatial and temporal variations of the Kuroshio East of Taiwan, 1982–2005: a numerical study. J Geophys Res 113:C04002. doi: 10.1029/2007JC004485 CrossRefGoogle Scholar
  7. Hsin YC, Qu T, Wu CR (2010) Intra-seasonal variation of the Kuroshio southeast of Taiwan and its possible forcing mechanism. Ocean Dyn 60:1293–1306. doi: 10.1007/s10236-010-0294-2 Google Scholar
  8. Hsin YC, Wu CR, Chao SY (2012) An updated examination of the Luzon Strait transport. J Geophys Res 117:C03022. doi: 10.1029/2011JC007714 CrossRefGoogle Scholar
  9. Kohonen T (1982) Self-organized formation of topologically correct features maps. Biol Cybern 43:59–69CrossRefGoogle Scholar
  10. Kohonen T (2001) Self-organizing maps. Springer Series in Information Sciences, Vol. 30, 3d ed., Springer-Verlag, pp 501Google Scholar
  11. Liang WD, Yang YJ, Tang TY, Chung WS (2008) Kuroshio in the Luzon Strait. J Geophys Res 113:C08048. doi: 10.1029/2007JC004609 CrossRefGoogle Scholar
  12. Liu Y, Weisberg RH (2005) Patterns of ocean current variability on the West Florida Shelf using the self-organizing map. J Geophys Res 110:C06003. doi: 10.1029/2004JC002786 CrossRefGoogle Scholar
  13. Liu Y, Weisberg RH, He R (2006a) Sea surface temperature patterns on the West Florida Shelf using the growing hierarchical self-organizing maps. J Atmos Oceanic Tech 23(2):325–338CrossRefGoogle Scholar
  14. Liu Y, Weisberg RH, Mooers CNK (2006b) Performance evaluation of the self-organizing map for feature extraction. J Geophys Res 111:C05018. doi: 10.1029/2005JC003117 CrossRefGoogle Scholar
  15. Liu Y, Weisberg RH, Yuan Y (2008) Patterns of upper layer circulation variability in the South China Sea from satellite altimetry using the self-organizing map. Acta Oceanol Sin 27(Supp):129–144Google Scholar
  16. Mau JC, Wang DP, Ullman DS, Codiga DL (2007) Characterizing long island sound outflows from HF radar using self-organizing maps. Estuarine Coastal Shelf Sci 74:155–165CrossRefGoogle Scholar
  17. Nitani H (1972) Beginning of the Kuroshio. In: H. Stommel and K. Yoshida (eds) Kuroshio—its physical aspects, University of Tokyo Press, 129–163Google Scholar
  18. Qiu B, Chen S (2010) Eddy-mean flow interaction in the decadally modulating Kuroshio extension system. Deep Sea Res II 57:1098–1110CrossRefGoogle Scholar
  19. Qu T, Lukas R (2003) The bifurcation of the north equatorial current in the pacific. J Phys Oceanogr 33:5–18CrossRefGoogle Scholar
  20. Richardson AJ, Risien C, Shillington FA (2003) Using self-organizing maps to identify patterns in satellite imagery. Prog Oceanogr 59:223–239CrossRefGoogle Scholar
  21. Shaw PT (1991) The seasonal variation of the intrusion of the Philippine Sea water into the South China Sea. J Geophys Res 96:821–827CrossRefGoogle Scholar
  22. Sheremet VA (2001) Hysteresis of a western boundary current leaping across a gap. J Phys Oceanogr 31:1247–1259CrossRefGoogle Scholar
  23. Sheu WJ, Wu CR, Oey LY (2010) Blocking and westward passage of eddies in the Luzon Strait. Deep Sea Res II 57:1783–1791CrossRefGoogle Scholar
  24. Wu CR, Chiang TL (2007) Mesoscale eddies in the northern South China Sea. Deep Sea Res II 54:1575–1588CrossRefGoogle Scholar
  25. Wu CR, Tang TY, Lin SF (2005) Intra-seasonal variation in the velocity field of the northeastern South China Sea. Cont Shelf Res 25:2075–2083CrossRefGoogle Scholar
  26. 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: 10.1029/2005JC003412 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  1. 1.Department of Earth SciencesNational Taiwan Normal UniversityTaipeiRepublic of China

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