Oceanography The Official Magazine of
The Oceanography Society
Volume 28 Issue 04

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Volume 28, No. 4
Pages 54 - 63

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The Kuroshio and Luzon Undercurrent East of Luzon Island

By Ren-Chieh Lien , Barry Ma, Craig M. Lee, Thomas B. Sanford, Vigan Mensah , Luca R. Centurioni , Bruce D. Cornuelle, Ganesh Gopalakrishnan, Arnold L. Gordon , Ming-Huei Chang , Steve R. Jayne , and Yiing Jang Yang 
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Article Abstract

Current structure, transport, and water mass properties of the northward-flowing Kuroshio and the southward-flowing Luzon Undercurrent (LU) were observed for nearly one year, June 8, 2012–June 4, 2013, across the Kuroshio path at 18.75°N. Observations were made from four platforms: an array of six subsurface ADCP moorings, two Seagliders, fivepressure inverted echo sounders (PIES), and five horizontal electric field (HEF) sensors, providing the most detailed time series of the Kuroshio and Luzon Undercurrent water properties to date. Ocean state estimates of the western boundary current system were performed using the MIT general circulation model—four-dimensional variational assimilation (MITgcm-4D-Var) system. Prominent Kuroshio features from observations are simulated well by the numerical model. Annual mean Kuroshio transport, averaged over all platforms, is ~16 Sv with a standard deviation ~4 Sv. Kuroshio and LU transports and water mass pathways east of Luzon are revealed by Seaglider measurements. In a layer above the salinity maximum associated with North Pacific Tropical Water (NPTW), Kuroshio transport is ~7 Sv and contains North Equatorial Current (NEC) and Western Philippine Sea (WPS) waters, with an insignificant amount of South China Sea water on the shallow western flank. In an intermediate layer containing the core of the NPTW, Kuroshio transport is ~10 Sv, consisting mostly of NEC water. In the lower layer of the Kuroshio, transport is ~1.5 Sv of mostly North Pacific Intermediate Water (NPIW) as a part of WPS waters. Annual mean Luzon Undercurrent southward transport integrated to 1,000 m depth is ~2.7 Sv with a standard deviation ~2 Sv, carrying solely WPS waters below the salinity minimum of the NPIW. The transport of the western boundary current integrated over the full ocean depth east of Luzon Island is ~14 ± 4.5 Sv. Sources of the water masses in the Kuroshio and Luzon Undercurrent are confirmed qualitatively by the numerical model.

Citation

Lien, R.-C., B. Ma, C.M. Lee, T.B. Sanford, V. Mensah, L.R. Centurioni, B.D. Cornuelle, G. Gopalakrishnan, A.L. Gordon, M.-H. Chang, S.R. Jayne, and Y.J. Yang. 2015. The Kuroshio and Luzon Undercurrent east of Luzon Island. Oceanography 28(4):54–63, https://doi.org/10.5670/oceanog.2015.81.

References
    Andres, M., S. Jan, T.B. Sanford, V. Mensah, L.R. Centurioni, and J.W. Book. 2015. Mean structure and variability of the Kuroshio from northeastern Taiwan to southwestern Japan. Oceanography 28(4):84–95, https://doi.org/​10.5670/oceanog.2015.84.
  1. Andres, M., M. Wimbush, J.-H. Park, K.-I. Chang, B.-H. Lim, D.R. Watts, H. Ichikawa, and W.J. Teague. 2008. Observations of Kuroshio flow variations in the East China Sea. Journal of Geophysical Research 113, C05013, https://doi.org/​10.1029/2007JC004200.
  2. Aoyama, J., S. Watanabe, M.J. Miller, N. Mochioka, and T. Otake. 2014. Spawning sites of the Japanese eel in relation to oceanographic structure and the West Mariana Ridge. PLoS ONE 9(2):e88759, https://doi.org/10.1371/journal.pone.0088759.
  3. Centurioni, L.R., P.P. Niiler, and D.-K. Lee. 2004. Observations of inflow of Philippine Sea water into the South China Sea through the Luzon Strait. Journal of Physical Oceanography 34:113–121, https://doi.org/10.1175/1520-0485(2004)034​<0113:OOIOPS>2.0.CO;2.
  4. Chang, Y.L., Y. Miyazawa, and X. Guo. 2015. Effects of the STCC eddies on the Kuroshio based on the 20-year JCOPE2 reanalysis results. Progress in Oceanography 135:64–76, https://doi.org/​10.1016/j.pocean.2015.04.006.
  5. Chave, A.D., and D.S. Luther. 1990. Low frequency, motionally induced electromagnetic fields in the ocean: Part 1. Theory. Journal of Geophysical Research 95:7,185–7,200, https://doi.org/10.1029/JC095iC05p07185.
  6. Chern, C.-S., and J. Wang. 2005. Interactions of mesoscale eddy and western boundary current: A reduced-gravity numerical model study. Journal of Oceanography 61:271–282, https://doi.org/​10.1007/s10872-005-0037-z.
  7. Donohue, K.A., D.R. Watts, K.L. Tracey, A.D. Greene, and M. Kennelly. 2010. Mapping circulation in the Kuroshio Extension with an array of current and pressure recording inverted echo sounders. Journal of Atmospheric and Oceanic Technology 27:507–527, https://doi.org/​10.1175/2009JTECHO686.1
  8. Early, J.J., R.M. Samelson, and D.B. Chelton. 2011. The evolution and propagation of quasigeostrophic ocean eddies. Journal of Physical Oceanography 41:1,535−1,555, https://doi.org/​10.1175/2011JPO4601.1.
  9. Eriksen, C.C., T.J. Osse, R.D. Light, T. Wen, T.W. Lehman, P.L. Sabin, J.W. Ballard, and A.M. Chiodi. 2001. Seaglider: A long-range autonomous underwater vehicle for oceanographic research. IEEE Journal of Oceanic Engineering 26(4):424–436, https://doi.org/​10.1109/48.972073.
  10. Gordon, A.L., P. Flament, C. Villanoy, and L. Centurioni. 2014. The nascent Kuroshio of Lamon Bay. Journal of Geophysical Research 119:4,251–4,263, https://doi.org/​10.1002/2014JC009882.
  11. Hansen, D.V., and P.M. Poulain. 1996. Quality control and interpolations of WOCE-TOGA drifter data. Journal of Atmospheric and Oceanic Technology 13(4):900–909, https://doi.org/​10.1175/1520-0426(1996)013<0900:QCAIOW>​2.0.CO;2.
  12. Hasunuma, K., and K. Yoshida. 1978. Splitting of the subtropical gyre in the western north Pacific. Journal of the Oceanographic Society of Japan 34:160–172, https://doi.org/10.1007/BF02108654.
  13. Hu, D., and M. Cui. 1991. The western boundary current of the Pacific and its role in the climate. Chinese Journal of Oceanology and Limnology 9(1):1–14, https://doi.org/10.1007/BF02849784
  14. Hu, D.-X., S.-J. Hu, L.-X. Wu, L. Li, L.-L. Zhang, X.-Y. Diao, Z.-H. Chen, Y.-L. Li, F. Wang, and D.-L. Yuan. 2013. Direct measurements of the Luzon Undercurrent. Journal of Physical Oceanography 43(7):1,417–1,425, https://doi.org/10.1175/JPO-D-12-0165.1
  15. Jan, S., Y.-J. Yang, J. Wang, V. Mensah, T.-H. Kuo, M.-D. Chiou, C.-S. Chern, M.-H. Chang, and H. Chien. 2015. Large variability of the Kuroshio at 23.75°N east of Taiwan. Journal of Geophysical Research 120:1,825–1,840, https://doi.org/​10.1002/2014JC010614
  16. Johns, W.E., D.R. Watts, and H.T. Rossby. 1989. A test of geostrophy in the Gulf Stream. Journal of Geophysical Research 94:3,211–3,222, https://doi.org/10.1029/JC094iC03p03211
  17. Kim, Y.Y., T. Qu, T. Jensen, T. Miyama, H. Mitsudera, H.-W. Kang, and A. Ishida. 2004. Seasonal and interannual variations of the North Equatorial Current bifurcation in a high resolution OGCM. Journal of Geophysical Research 109, C03040, https://doi.org/10.1029/2003JC002013.
  18. Kuo, Y., and C.-S. Chern. 2011. Numerical study on the interactions between a mesoscale eddy and a western boundary current. Journal of Oceanography 67:263–272, https://doi.org/​10.1007/s10872-011-0026-3.
  19. Lien, R.-C., B. Ma, Y.-H. Cheng, C.-R. Ho, B. Qiu, C.M. Lee, and M.-H. Chang. 2014. Modulation of Kuroshio transport by mesoscale eddies at the Luzon Strait entrance. Journal of Geophysical Research 119:2,129–2,142, https://doi.org/​10.1002/2013JC009548
  20. Lumpkin, R., S.A. Grodsky, L. Centurioni, M.-H. Rio, J.A. Carton, and D. Lee. 2013. Removing spurious low-frequency variability in drifter velocities. Journal of Atmospheric and Oceanic Technology 30(2):353–360, https://doi.org/​10.1175/jtech-d-12-00139.1.
  21. Marshall, J., A. Adcroft, C. Hill, L. Perelman, and C. Heisey. 1997. A finite-volume, incompressible Navier Stokes model for studies of the ocean on parallel computers. Journal of Geophysical Research 102(C3):5,753–5,766, https://doi.org/​10.1029/96JC02775.
  22. Maximenko, N., R. Lumpkin, and L. Centurioni. 2013. Ocean surface circulation. International Geophysics 103: 283–304, https://doi.org/10.1016/B978-0-12-391851-2.00012-X. (Special issue on Ocean Circulation and Climate: A 21st Century Perspective. G. Siedler, S.M. Griffies, J. Gould, and J.A. Church, eds.)
  23. Meinen, C.S., D.S. Luther, D.R. Watts, K.L. Tracey, A.D. Chave, and J. Richman. 2002. Combining inverted echo sounder and horizontal electric field recorder measurements to obtain absolute velocity profiles. Journal of Atmospheric and Oceanic Technology 19:1,653-1,664, https://doi.org/10.1175/1520-0426(2002)019<1653:CIESAH>2.0.CO;2.
  24. Meinen, C.S., and D.R. Watts. 2000. Vertical structure and transport on a transect across the North Atlantic Current near 42°N: Time series and mean. Journal of Geophysical Research 105:21,869–21,892, https://doi.org/​10.1029/2000JC900097
  25. Mensah, V., S. Jan, M.-H. Chang, and Y.J. Yang. 2015. Intraseasonal to seasonal variability of intermediate waters along the Kuroshio path east of Taiwan. Journal of Geophysical Research 120:5,473–5,489, https://doi.org/10.1002/2015JC010768.
  26. Mensah, V., S. Jan, M.-D. Chiou, T.-H. Kuo, and R.-C. Lien. 2014. Evolution of the Kuroshio tropical water from the Luzon Strait to the east of Taiwan. Deep Sea Research Part I 86:68–81, https://doi.org/10.1016/j.dsr.2014.01.005
  27. Niiler, P.P. 2001. The world ocean surface circulation. Pp. 193–204 in Ocean Circulation and Climate. G. Siedler, J. Church, and J. Gould, eds, Academic Press.
  28. Niiler, P.P., A. Sybrandy, K. Bi, P.M. Poulain, and D. Bitterman. 1995. Measurements of the water-​following capability of holey-sock and TRISTAR drifters. Deep Sea Research Part I 42:1,951–1,964, https://doi.org/10.1016/0967-0637(95)00076-3.
  29. Nitani, H. 1972. Beginning of the Kuroshio. Pp. 129–163 in Kuroshio: Its Physical Aspects. H. Stommel and K. Yoshida, eds, University of Tokyo Press, Tokyo.
  30. Pazan, E.E., and P.P. Niiler, 2001. Recovery of near-surface velocity from undrogued drifters. Journal of Atmospheric and Oceanic Technology 18(3):476–489, https://doi.org/10.1175/1520-0426(2001)018<0476:RONSVF>2.0.CO;2
  31. Qiu, B., and R. Lukas. 1996. Seasonal and interannual variability of the North Equatorial Current, the Mindanao Current and the Kuroshio along the Pacific western boundary. Journal of Geophysical Research 101:12,315–12,330, https://doi.org/​10.1029/95JC03204
  32. Qiu, B., D.L. Rudnick, I. Cerovecki, B.D. Cornuelle, S. Chen, M.C. Schönau, J.L. McClean, and G. Gopalakrishnan. 2015. The Pacific North Equatorial Current: New insights from the origins of the Kuroshio and Mindanao Currents (OKMC) Project. Oceanography 28(4):24–33, https://doi.org/10.5670/oceanog.2015.78.
  33. Qu, T.D., T. Kagimoto, and T. Yamagata. 1997. A subsurface countercurrent along the east coast of Luzon. Deep Sea Research Part I 44:413–423, https://doi.org/10.1016/S0967-0637(96)00121-5
  34. Qu, T., and R. Lukas. 2003. The bifurcation of the North Equatorial Current in the Pacific. Journal of Physical Oceanography 33:5–18, https://doi.org/10.1175/1520-0485(2003)033​<0005:TBOTNE>2.0.CO;2.
  35. Qu, T., H. Mitsudera, and T. Yamagata. 1998. On the western boundary currents in the Philippine Sea. Journal of Geophysical Research 103:7,537–7,548, https://doi.org/10.1029/98JC00263.
  36. Rudnick, D.L., S. Jan, L. Centurioni, C.M. Lee, R.-C. Lien, J. Wang, D.-K. Lee, R.-S. Tseng, Y.Y. Kim, and C.-S. Chern. 2011. Seasonal and mesoscale variability of the Kuroshio near its origin. Oceanography 24(4):52–63, https://doi.org/​10.5670/oceanog.2011.94.
  37. Sanford, T.B. 1971. Motionally induced electric and magnetic fields in the sea. Journal of Geophysical Research 76(15):3,476-3,492, https://doi.org/​10.1029/JC076i015p03476.
  38. Schönau, M.C., D.L. Rudnick, I. Cerovecki, G. Gopalakrishnan, B.D. Cornuelle, J.L. McClean, and B. Qiu. 2015. The Mindanao Current: Mean structure and connectivity. Oceanography 28(4):34–45, https://doi.org/10.5670/oceanog.2015.79.
  39. Sherman, J., R.E. Davis, W.B. Owens, and J. Valdes. 2001. The autonomous underwater glider “Spray.” IEEE Journal of Oceanic Engineering 26:437–446, https://doi.org/10.1109/48.972076
  40. Sun, C., and D.R. Watts. 2001. A circumpolar gravest empirical mode for the Southern Ocean hydrography. Journal of Geophysical Research 106(C2):2,833-2,855, https://doi.org/​10.1029/2000JC900112.
  41. Sverdrup, H.U. 1942. Oceanography for Meteorologists. Prentice Hall, New York, 246 pp. 
  42. Talley, L.D., 1993. Distribution and formation of North Pacific Intermediate Water. Journal of Physical Oceanography 23:517–537, https://doi.org/10.1175/1520-0485(1993)023​<0517:DAFONP>2.0.CO;2.
  43. Talley, L.D., G.L. Pickard, W.J. Emery, and J.H. Swift. 2010. Descriptive Physical Oceanography: An Introduction, 6th ed. Elsevier, 560 pp.
  44. Watts, D.R., X. Qian, and K.L. Tracey. 2001. Mapping abyssal current and pressure fields under the meandering Gulf Stream. Journal of Atmospheric and Oceanic Technology 18:1,052–1,067, https://doi.org/10.1175/1520-0426(2001)018​<1052:MACAPF>2.0.CO;2
  45. Watts, D.R., and H.T. Rossby. 1977. Measuring dynamic heights with inverted echo sounders: Results from MODE. Journal of Physical Oceanography 7:345–358, https://doi.org/​10.1175/1520-0485(1977)007<0345:MDHWIE>​2.0.CO;2
  46. Yang, J., X. Lin, and D. Wu. 2013. On the dynamics of the seasonal variation in the South China Sea throughflow transport. Journal of Geophysical Research 118:1–13, https://doi.org/​10.1002/2013JC009367.
  47. Yang, K.-C., J. Wang, C.M. Lee, B. Ma, R.-C. Lien, S. Jan, Y.J. Yang, and M.-H. Chang. 2015. Two mechanisms cause dual velocity maxima in the Kuroshio east of Taiwan. Oceanography 28(4):64–73, https://doi.org/​10.5670/oceanog.2015.82.
  48. Yang, Y., C.-T. Liu, J.-H. Hu, and M. Koga. 1999. Taiwan Current (Kuroshio) and impinging eddies. Journal of Oceanography 55:609–617, https://doi.org/​10.1023/A:1007892819134
  49. Yaremchuk, M., and T. Qu. 2004. Seasonal variability of the large-scale currents near the coast of the Philippines. Journal of Physical Oceanography 34(4):844–855, https://doi.org/​10.1175/​1520-0485(2004)034​<0844:SVOTLC>​2.0.CO;2
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