The currents in the low-latitude western North Pacific are critical to the general circulation. The North Equatorial Current flows westward, bifurcating off the coast of the Philippines to form the northward-flowing Kuroshio and the southward-flowing Mindanao Current. Below the thermocline, undercurrents flow opposite to the currents above and include the southward-flowing Luzon Undercurrent, the northward-flowing Mindanao Undercurrent, and an eastward-flowing series of North Equatorial Undercurrents. Two complementary programs, Origins of the Kuroshio and Mindanao Current (OKMC) and Observations of Kuroshio Transport and Variability (OKTV), focused on observations and modeling of these currents. Results address the region’s circulation, water masses, and eddies. The connectivity between the currents as determined by water masses is of special interest.

Rudnick, D.L., S. Jan, and C.M. Lee. 2015. A new look at circulation in the western North Pacific. Oceanography 28(4):16–23, https://doi.org/10.5670/oceanog.2015.77.

Andres, M., J.H. Park, M. Wimbush, X.H. Zhu, K.I. Chang, and H. Ichikawa. 2008a. Study of the Kuroshio/Ryukyu current system based on satellite-altimeter and in situ measurements. Journal of Oceanography 64:937–950, https://doi.org/​10.1007/s10872-008-0077-2.

Andres, M., M. Wimbush, J.H. Park, K.I. Chang, B.H. Lim, D.R. Watts, H. Ichikawa, and W.J. Teague. 2008b. Observations of Kuroshio flow variations in the East China Sea. Journal of Geophysical Research 113, C05013, https://doi.org/​10.1029/2007JC004200.

Centurioni, L.R., P.P. Niiler, and D.K. Lee. 2004. Observations of inflow of Philippine Sea surface 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.

Fine, R.A., R. Lukas, F.M. Bingham, M.J. Warner, and R.H. Gammon. 1994. The western equatorial Pacific: A water mass crossroads. Journal of Geophysical Research 99:25,063–25,080, https://doi.org/​10.1029/94JC02277.

Ganachaud, A., S. Cravatte, A. Melet, A. Schiller, N.J. Holbrook, B.M. Sloyan, M.J. Widlansky, M. Bowen, J. Verron, P. Wiles, and others. 2014. The Southwest Pacific Ocean Circulation and Climate Experiment (SPICE). Journal of Geophysical Research 119:7,660–7,686, https://doi.org/10.1002/2013jc009678.

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.

Gu, D.F., and S.G.H. Philander. 1997. Interdecadal climate fluctuations that depend on exchanges between the tropics and extratropics. Science 275:805–807, https://doi.org/10.1126/science.275.5301.805.

Hu, D.X., W.J. Cai, A. Ganachaud, W.S. Kessler, and J. Sprintall. 2015a. Introduction to special section on western Pacific Ocean circulation and climate. Journal of Geophysical Research 120:3,175–3,176, https://doi.org/10.1002/2015jc010856.

Hu, D.X., L.X. Wu, W.J. Cai, A. Sen Gupta, A. Ganachaud, B. Qiu, A.L. Gordon, X.P. Lin, Z.H. Chen, S.J. Hu, and others. 2015b. Pacific western boundary currents and their roles in climate. Nature 522:299–308, https://doi.org/10.1038/nature14504.

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.

Kim, Y.Y., T.D. 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.

Kimura, S., T. Inoue, and T. Sugimoto. 2001. Fluctuation in the distribution of low-salinity water in the North Equatorial Current and its effect on the larval transport of the Japanese eel. Fisheries Oceanography 10:51–60, https://doi.org/​10.1046/j.1365-2419.2001.00159.x.

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.

Mensah, V., S. Jan, M.H. Chang, and Y.J. Yang. 2015. Intraseasonal to seasonal variability of the intermediate waters along the Kuroshio path east of Taiwan. Journal of Geophysical Research 120:5,473–5,489, https://doi.org/​10.1002/2015JC010768.

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.

Qiu, B., and S.C. Chen. 2010. Interannual-to-decadal variability in the bifurcation of the North Equatorial Current off the Philippines. Journal of Physical Oceanography 40:2,525–2,538, https://doi.org/​10.1175/2010jpo4462.1.

Qiu, B., S. Chen, D.L. Rudnick, and Y. Kashino. 2015. A new paradigm for the North Pacific subthermocline low-latitude western boundary current system. Journal of Physical Oceanography 45:2,407–2,423, https://doi.org/10.1175/JPO-D-15-0035.1.

Qiu, B., S.M. Chen, and H. Sasaki. 2013a. Generation of the North Equatorial Undercurrent jets by triad baroclinic Rossby wave interactions. Journal of Physical Oceanography 43:2,682–2,698, https://doi.org/10.1175/Jpo-D-13-099.1.

Qiu, B., D.L. Rudnick, S.M. Chen, and Y. Kashino. 2013b. Quasi-stationary North Equatorial Undercurrent jets across the tropical North Pacific Ocean. Geophysical Research Letters 40:2,183–2,187, https://doi.org/10.1002/grl.50394.

Qu, T.D., 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.

Roemmich, D., and J. Gilson. 2009. The 2004–2008 mean and annual cycle of temperature, salinity, and steric height in the global ocean from the Argo Program. Progress in Oceanography 82:81–100, https://doi.org/10.1016/J.Pocean.2009.03.004.

Rudnick, D.L., R.E. Davis, C.C. Eriksen, D.M. Fratantoni, and M.J. Perry. 2004. Underwater gliders for ocean research. Marine Technology Society Journal 38:73–84, https://doi.org/​10.4031/002533204787522703.

Rudnick, D.L., S. Jan, L. Centurioni, C. Lee, R.-C. Lien, J. Wang, D.-K. Lee, R.-T. Tseng, Y.Y. Kim, and C.-S. Chern. 2011. Seasonal and mesoscale variability of the Kuroshio near its origin. Oceanography 24:52–63, https://doi.org/​10.5670/oceanog.2011.94.

Schönau, M.C., and D.L. Rudnick. 2015. Glider observations of the North Equatorial Current in the western tropical Pacific. Journal of Geophysical Research 120:3,586–3,605, https://doi.org/​10.1002/2014JC010595.

Toole, J.M., R.C. Millard, Z. Wang, and S. Pu. 1990. Observations of the Pacific North Equatorial Current bifurcation at the Philippine coast. Journal of Physical Oceanography 20, 307-318, https://doi.org/10.1175/1520-0485(1990)020​<0307:OOTPNE>2.0.CO;2.

This is an open access article made available under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution, and reproduction in any medium or format as long as users cite the materials appropriately, provide a link to the Creative Commons license, and indicate the changes that were made to the original content. Images, animations, videos, or other third-party material used in articles are included in the Creative Commons license unless indicated otherwise in a credit line to the material. If the material is not included in the article’s Creative Commons license, users will need to obtain permission directly from the license holder to reproduce the material.