Interannual volume transport anomalies in the far western tropical North Pacific were calculated using the Western Pacific Ocean State Estimates (WPOSE; 2009–2017; 115°E−170°E, 15°S–27°N) to assess the magnitude, phase, and vertical structure of volume transport, and the relationship of interannual transport to the El Niño-Southern Oscillation phenomena. The mean velocity and thermohaline structure for the WPOSE were verified using Argo climatology and autonomous glider observations. Transport was calculated for both an upper layer (surface-26 kg m⁻³) and a lower layer (26–27.3 kg m⁻³). Annual volume transport anomalies were small north of 8°N but varied by 50% of the mean volume transport between the equator and 8°N. Interannual anomalies exceeded annual anomalies throughout the region. Volume transports of the North Equatorial Current, the Mindanao Current, and the South Equatorial Current/New Guinea Coastal Undercurrent increased beginning in September 2014, leading to a large increase in transport in the North Equatorial Counter Current before the mature phase of El Niño in 2015/2016. The increase in transport was related to the meridional gradient in thermocline depth centered at 5°N at the southern part of the Mindanao Dome, where extreme shoaling of the thermocline took place. Lower-layer volume transports were not always in phase with those of the upper-layer and made considerable contributions to total transport variability.

Key Points

Volume transport variability was greatest equatorward of 8°N, at the intersection of North and South Pacific currents
Subthermocline (lower-layer) interannual volume transport anomalies were of the same magnitude of those of the thermocline (upper-layer)
Interannual volume transport anomalies in the western tropical North Pacific increased before the mature 2015/2016 El Niño event

Plain Language Summary

The Western Pacific Ocean State Estimates (WPOSE) estimate the ocean state by combining observations and ocean model simulations through data assimilation. These estimates were made from 2009 to 2017 in the far western tropical Pacific. This region encompasses warm, tropical surface water and subtropical thermocline water (upper-layer) and polar intermediate water (lower-layer) that are sourced from the North and South Pacific and spread into the Indian Ocean through the Indonesian throughflow. The WPOSE were used to calculate volume transports to understand the modulation of major ocean currents as a system. Annual volume transport variability was small to the north of 8°N, and large to the south of 8°N and near the equator. Interannual volume transport variability was much greater than annual variability for both the upper and lower isopycnal layers and had a clear relationship with the El Niño-Southern Oscillation phenomenon. The period encompassed two El Niño events, a weak event in 2009/2010, and a strong event in 2015/2016. Regional transport increased during both events, but in the 2015/2016 El Niño, an increase in volume transport led the El Niño event by 2–3 months.

Open Research

Data Availability Statement

Glider data are available at spraydata.ucsd.edu (Rudnick, 2020). The WPOSE are available upon request to B. Cornuelle and G. Gopalakrishnan and as the Northwest Pacific State Estimate/Reanalysis (NWPac) at http://www.ecco.ucsd.edu/nwpac.html. The 1/12° global HYCOM/NCODA Ocean Reanalysis was funded by the U.S. Navy and the Modeling and Simulation Coordination Office. Computer time was made available by the DoD High Performance Computing Modernization Program. The output is publicly available at http://hycom.org. The HYCOM/NCODA 1/12° global daily analysis can be obtained from the HYCOM Consortium (http://hycom.org/dataserver/). Roemmich and Gilson Argo Climatology are available at http://sio-argo.ucsd.edu/RG_Climatology.html. The Argo data are collected and made freely available by the International Argo Program and the national programs that contribute to it. (http://www.argo.ucsd.edu, http://argo.jcommops.org). The Argo Program is part of the Global Ocean Observing System (Argo, 2020). Aviso absolute dynamic topography MADT-H (2014), is available from CLS Space Oceanography Division at http://www.aviso.altimetry.fr/. The AVISO SSH maps used to compare to MADT WPOSE were obtained from the SSALTO/Developing Use of Altimetry for Climate Studies (DUACS) altimeter product on a ¼º longitude × ¼º latitude grid, produced and distributed by the Copernicus Marine and Environment Monitoring Service (CMEMS; http://marine.copernicus.eu/). The MITgcm code used in this study is checkpoint 64Y and can be obtained from http://mitgcm.org/. The along-track altimetry data can be obtained from Radar Altimetry Database System (RADS) (http://rads.tudelft.nl/rads/index.shtml). The SST data can be obtained from Remote Sensing Systems Inc (http://www.remss.com/). The NCEP/NCAR-Reanalysis-1 atmospheric forcings can be obtained from http://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.html.

References

Argo (2000). Argo float data and metadata from Global Data Assembly Centre (Argo GDAC). SEANOE. http://doi.org/10.17882/42182
Azminuddin, F., Lee, J. H., Jeon, D., Shin, C.-W., Villanoy, C., Lee, S., et al. (2021). Effect of the intensified sub-thermocline eddy on strengthening the Mindanao Undercurrent in 2019. Journal of Geophysical Research: Oceans, 127, e2021JC017883. https://doi.org/10.1029/2021JC017883
Bingham, F. M., & Lukas, R. (1994). The southward intrusion of North Pacific intermediate water along the Mindanao coast. Journal of Physical Oceanography, 24, 141–154. https://doi.org/10.1175/1520-0485(1994)024<0141:tsionp>2.0.co;2
Capotondi, A., Wittenberg, A. T., Kug, J.-S., Takahashi, K., & McPhaden, M. (2020). ENSO diversity. In A. Santoso, W. Cai, & M. McPhaden (Eds.), El Niño Southern Oscillation in a changing climate (pp. 65–86). American Geophysical Union. https://doi.org/10.1002/9781119548164.ch4
Chassignet, E. P., Hurlburt, H. E., Smedstad, O. M., Halliwell, G. R., Hogan, P. J., Wallcraft, A. J., et al. (2007). The HYCOM (HYbrid Coordinate Ocean Model) data assimilative system. Journal of Marine Systems, 65, 60–83. https://doi.org/10.1016/j.jmarsys.2005.09.016
Chen, L., Jia, Y., & Liu, Q. (2014). Mesoscale eddies in the Mindanao Dome region. Journal of Oceanography, 71, 133–140. https://doi.org/10.1007/s10872-014-0255-3
Chen, X., Qiu, B., Chen, S., Qi, Y., & Du, Y. (2015). Seasonal eddy kinetic energy modulations along the North Equatorial Countercurrent in the Western Pacific. Journal of Geophysical Research: Oceans, 120, 6351–6362. https://doi.org/10.1002/2015JC011054
Chiang, T.-L., & Qu, T. (2013). Subthermocline eddies in the Western Equatorial Pacific as shown by an eddy-resolving OGCM. Journal of Physical Oceanography, 43, 1241–1253. https://doi.org/10.1175/JPO-D-12-0187.1
Chiang, T.-L., Wu, C.-R., Qu, T., & Hsin, Y.-C. (2015). Activities of 50–80 day subthermocline eddies near the Philippine coast. Journal of Geophysical Research: Oceans, 120, 3606–3623. https://doi.org/10.1002/2013JC009626
Clarke, A. J. (2014). El Niño Physics and El Niño predictability. Annual Review of Marine Science, 6, 79–99. https://doi.org/10.1146/annurev-marine-010213-135026
Davis, R. E., Ohman, M. D., Rudnick, D. L., & Sherman, J. T. (2008). Glider surveillance of physics and biology in the southern California Current System. Limnology & Oceanography, 53, 2151–2168. https://doi.org/10.4319/lo.2008.53.5_part_2.2151
Dutrieux, P. (2009). Tropical Western Pacific currents and the origin of intraseasonal variability below the thermocline (Ph.D. thesis) (p. 150). University of Hawaii at Manoa. Pubmed Partial Author stitle stitle Volume Page., Structured.
Fine, R. A., Lukas, R., Bingham, F. M., Warner, M. J., & Gammon, R. H. (1994). The Western equatorial Pacific: A water mass crossroads. Journal of Geophysical Research, 99, 25063–25080. https://doi.org/10.1029/94JC02277
Firing, E., Kashino, Y., & Hacker, P. (2005). Energetic subthermocline currents observed east of Mindanao. Deep Sea Research Part II: Topical Studies in Oceanography, 52, 605–613. https://doi.org/10.1016/j.dsr2.2004.12.007
Germineaud, C., Ganachaud, A., Sprintall, J., Cravatte, S., Eldin, G., Alberty, M. S., & Privat, E. (2016). Pathways and water mass properties of the thermocline and intermediate waters in the Solomon Sea. Journal of Physical Oceanography, 46(10), 3031–3049. https://journals.ametsoc.org/view/journals/phoc/46/10/jpo-d-16-0107.1.xml
Gopalakrishnan, G., Cornuelle, B. D., Hoteit, I., Rudnick, D. L., & Owens, W. B. (2013). State estimates and forecasts of the loop current in the Gulf of Mexico using the MITgcm and its adjoint. Journal of Geophysical Research: Oceans, 118, 3292–3314. https://doi.org/10.1002/jgrc.20239
Gordon, A. L. (1986). Inter-ocean exchange of thermocline water. Journal of Geophysical Research, 91, 5037–5046. https://doi.org/10.1029/JC091iC04p05037
Gordon, A. L., & Fine, R. A. (1996). Pathways of water between the Pacific and Indian oceans in the Indonesian seas. Nature. https://doi.org/10.1038/379146a0
Gordon, A. L., Napitu, A., Huber, B. A., Gruenburg, L. K., Pujiana, K., Agustiadi, T., et al. (2019). Makassar strait throughflow seasonal and interannual variability: An overview. Journal of Geophysical Research: Oceans, 124, 3724–3736. https://doi.org/10.1029/2018jc014502
Gouriou, Y., & Toole, J. (1993). Mean circulation of the upper layers of the western equatorial Pacific Ocean. Journal of Geophysical Research, 98(22), 495–520. https://doi.org/10.1029/93jc02513
Heimbach, P., Hill, C., & Giering, R. (2002). Automatic generation of efficient adjoint code for a Parallel Navier-Stokes solver. Paper presented at the Computational Science—ICCS 2002 (pp. 1019–1028). Springer-Verlag. https://doi.org/10.1007/3-540-46080-2_107
Hsin, Y.-C., & Qiu, B. (2012a). Seasonal fluctuations of the surface North Equatorial Countercurrent (NECC) across the Pacific basin. Journal of Geophysical Research, 117. https://doi.org/10.1029/2011JC007794
Hsin, Y.-C., & Qiu, B. (2012b). The impact of Eastern-Pacific versus Central-Pacific El Niños on the North Equatorial Countercurrent in the Pacific Ocean. Journal of Geophysical Research, 117, C11017. https://doi.org/10.1029/2012JC008362
Hu, D., Wu, L., Cai, W., Gupta, A. S., Ganachaud, A., Qiu, B., et al. (2015). Pacific Western boundary currents and their roles in climate. Nature, 522, 299–308. https://doi.org/10.1038/nature14504
Hu, D. X., Cui, M. C., Qu, T. D., & Li, Y. X. (1991). A subsurface northward current off Mindanao identified by dynamic calculation. Oceanography of Asian Marginal Seas, 359–365. https://doi.org/10.1016/s0422-9894(08)70108-9
Hu, S., & Fedorov, A. V. (2019). The extreme El Niño of 2015–2016: The role of westerly and easterly wind bursts, and preconditioning by the failed 2014 event. Climate Dynamics, 52, 7339–7357. https://doi.org/10.1007/s00382-017-3531-2
Johnson, G. C., Sloyan, B. M., Kessler, W. S., & McTaggart, K. E. (2002). Direct measurements of upper ocean currents and water properties across the tropical Pacific during the 1990s. Progress in Oceanography, 52, 31–61. https://doi.org/10.1016/S0079-6611(02)00021-6
Johnston, T. M. S., & Merrifield, M. A. (2000). Interannual geostrophic current anomalies in the near-equatorial western Pacific. Journal of Physical Oceanography, 30(1), 3–14. https://doi.org/10.1175/1520-0485(2000)030<0003:igcait>2.0.co;2
Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D., Gandin, L., et al. (1996). The NCEP/NCAR 40-year reanalysis project. Bulletin of the American Meteorological Society, 77, 437–471. https://doi.org/10.1175/1520-0477(1996)077<0437:tnyrp>2.0.co;2
Kashino, Y., Ishida, A., & Hosoda, S. (2011). Observed ocean variability in the Mindanao Dome Region. Journal of Physical Oceanography, 41(2), 287–302. https://journals.ametsoc.org/view/journals/phoc/41/2/2010jpo4329.1
Kawabe, M., Kashino, Y., & Kuroda, Y. (2008). Variability and linkages of New Guinea coastal undercurrent and lower equatorial intermediate current. Journal of Physical Oceanography, 38, 1780–1793. https://doi.org/10.1175/2008JPO3916.1
Kessler, W., Hristova, H., & Davis, R. E. (2019). Equatorward western boundary transport from the South Pacific: Glider observations, dynamics and consequences. Progress in Oceanography, 174, 208–225. https://doi.org/10.1016/j.pocean.2019.04.005
Kessler, W. S. (1990). Observations of long Rossby waves in the northern tropical Pacific. Journal of Geophysical Research, 95, 5183–5217. https://doi.org/10.1029/JC095iC04p05183
Kessler, W. S., & Cravatte, S. (2013). ENSO and short-term variability of the South Equatorial Current entering the Coral Sea. Journal of Physical Oceanography, 43, 956–969. https://doi.org/10.1175/JPO-D-12-0113.1
Kim, Y. Y., Qu, T., Jensen, T., Miyama, T., Mitsudera, H., Kang, H.-W., & Ishida, A. (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
Kuroda, Y. (2000). Variability of currents off the northern coast of New Guinea. Journal of Oceanography, 56, 103–116.
Lien, R.-C., Ma, B., Lee, C. M., Sanford, T. B., Mensah, V., Centurioni, L. R., et al. (2015). The Kuroshio and Luzon Undercurrent east of Luzon Island. Oceanography, 28(4), 54–63. https://doi.org/10.5670/oceanog.2015.81
Lindstrom, E., Lukas, R., Fine, R., Firing, E., Godfrey, S., Meyers, G., & Tsuchiya, M. (1987). The western equatorial Pacific Ocean circulation study. Nature, 330, 533–537. https://doi.org/10.1038/330533a0
Li, M., Yuan, D., Gordon, A. L., Gruenburg, L. K., Li, X., Li, R., et al. (2021). A strong Sub-Thermocline intrusion of the North Equatorial Subsurface Current into the Makassar Strait in 2016–2017. Geophysical Research Letters, 48, e2021GL092505. https://doi.org/10.1029/2021GL092505
Li, X., Yuan, D., Li, Y., Wang, Z., Wang, J., Hu, X., et al. (2021). Moored observations of currents and water mass properties between talaud and Halmahera Islands at the entrance of the Indonesian Seas. Journal of Physical Oceanography, 51(12), 3557–3572. https://journals.ametsoc.org/view/journals/phoc/51/12/JPO-D-21-0048.1.xml
Lu, Q., Ruan, Z., Wang, D.-P., Chen, D., & Wu, Q. (2017). Zonal transport from the western boundary and its role in warm water volume changes during ENSO. Journal of Physical Oceanography, 47, 211–225. https://doi.org/10.1175/JPO-D-16-0112.1
Marshall, J., Hill, C., Perelman, L., & Adcroft, A. (1997). Hydrostatic, quasi-hydrostatic, and nonhydrostatic ocean modeling. Journal of Geophysical Research, 102, 5733–5752. https://doi.org/10.1029/96JC02776
Masumoto, Y., & Yamagata, T. (1991). Response of the western tropical Pacific to the Asian winter monsoon: The generation of the Mindanao Dome. Journal of Physical Oceanography, 21, 1386–1398. https://doi.org/10.1175/1520-0485(1991)021<1386:rotwtp>2.0.co;2
McClean, J. L., Bader, D. C., Bryan, F. O., Maltrud, M. E., Dennis, J. M., Mirin, A. A., et al. (2011). A prototype two-decade fully-coupled fine-resolution CCSM simulation. Ocean Modelling, 39, 10–30. https://doi.org/10.1016/j.ocemod.2011.02.011
McPhaden, M. J. (2015). Playing hide and seek with El Niño. Nature Climate Change, 5, 791–795. https://doi.org/10.1038/nclimate2775
McPhaden, M. J., Busalacchi, A. J., Cheney, R., Donguy, J.-R., Gage, K. S., Halpern, D., et al. (1998). The tropical ocean-global atmosphere observing system: A decade of progress. Journal of Geophysical Research, 103, 14169–14240. https://doi.org/10.1029/97JC02906
Mean absolute dynamic topography MADT-H. (2014). CLS space oceanography division with help from Cnes Aviso. Retrieved from http://www.aviso.altimetry.fr/. Accessed 16 August 2016.
Meinen, C. S., & McPhaden, M. J. (2000). Observations of warm water volume changes in the equatorial Pacific and their relationship to El Niño and La Niña. Journal of Climate, 13(20), 3551–3559. https://doi.org/10.1175/1520-0442(2000)013<3551:OOWWVC>2.0.CO;2,
Meinen, C. S., & McPhaden, M. J. (2001). Interannual variability in warm water volume transports in the equatorial Pacific during 1993–99. Journal of Physical Oceanography, 31, 1324–1345. https://doi.org/10.1175/1520-0485(2001)031<1324:iviwwv>2.0.co;2
Qiu, B., & Chen, S. (2010). Interannual-to-decadal variability in the bifurcation of the North Equatorial Current off the Philippines. Journal of Physical Oceanography, 40, 2525–2538. https://doi.org/10.1175/2010JPO4462.1
Qiu, B., Chen, S., Powell, B. S., Colin, P. L., Rudnick, D. L., Schönau, M. C., et al. (2019). Nonlinear short-term upper ocean circulation variability in the tropical western Pacific. Oceanography, 28(4), 22–31. https://doi.org/10.5670/oceanog.2015.78
Qiu, B., Chen, S., & Sasaki, H. (2013). Generation of the North Equatorial Undercurrent jets by Triad baroclinic Rossby wave interactions. Journal of Physical Oceanography, 43, 2682–2698. https://doi.org/10.1175/JPO-D-13-099.1
Qiu, B., & Lukas, R. (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, 12315–12330. https://doi.org/10.1029/95JC03204
Qiu, B., Rudnick, D., Cerovecki, I., Cornuelle, B., Chen, S., Schonau, M., et al. (2015). The Pacific North Equatorial Current: New insights from the origins of the Kuroshio and Mindanao Currents (OKMC) project. Oceanography, 24–33.
Qu, T., Gan, J., Ishida, A., Kashino, Y., Tozuka, T., & Schönau, M. (2008). Semiannual variation in the western tropical Pacific Ocean. Geophysical Research Letters, 35, L16602. https://doi.org/10.1029/2008GL035058
Qu, T., Kagimoto, T., & Yamagata, T. (1997). A subsurface countercurrent along the East Coast of Luzon. Deep-Sea Research Part I, 44, 413–423. https://doi.org/10.1175/1520-0485(2003)033<0005:tbotne>2.0.co;2
Qu, T., & Lukas, R. (2003). The bifurcation of the North Equatorial Current in the Pacific. Journal of Physical Oceanography, 33, 5–18.
Roemmich, D., & Gilson, J. (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. (2020). Origins of the Kuroshio and Mindanao Current [Data set]. stl Scripps Institution of Oceanography, Instrument Development Group. https://doi.org/10.21238/S8SPRAY9131
Rudnick, D. L., Owens, W. B., Johnston, T. M. S., Karnauskas, K. B., Jakoboski, J., & Todd, R. E. (2021). The equatorial current system west of the Galapagos Islands during the 2014-16 El Nino as observed by underwater gliders. Journal of Physical Oceanography, 51(1), 3–17. https://doi.org/10.1175/jpo-d-20-0064.1
Santoso, A., Hendon, H., Watkins, A., Power, S., Dommenget, D., England, M. H., et al. (2019). Dynamics and predictability of El Niño–Southern Oscillation: An Australian perspective on progress and challenges. Bulletin of the American Meteorological Society, 100, 403–420. https://doi.org/10.1002/2017rg000560
Santoso, A., McPhaden, M. J., & Cai, W. (2017). The defining characteristics of ENSO extremes and the strong 2015/2016 El Niño. Reviews of Geophysics, 55, 1079–1129. https://doi.org/10.1175/2011JCLI4169.1
Schneider, N. (1998). The Indonesian throughflow and the global climate system. Journal of Climate, 11, 676–689. https://doi.org/10.1175/1520-0442(1998)011%3C0676:TITATG%3E2.0.CO;2
Schönau, M. C. (2017). Transport and thermohaline structure in the western tropical North Pacific. UC San Diego.
Schönau, M. C., & Rudnick, D. L. (2015). Glider observations of the North Equatorial Current in the western tropical Pacific. Journal of Geophysical Research: Oceans, 120, 3586–3605. https://doi.org/10.1002/2014JC010595
Schönau, M. C., & Rudnick, D. L. (2017). Mindanao current and undercurrent: Thermohaline structure and transport from repeat glider observations. Journal of Physical Oceanography, 47, 2055–2075. https://doi.org/10.1175/jpo-d-16-0274.1
Schönau, M. C., Rudnick, D., Cerovecki, I., Gopalakrishnan, G., Cornuelle, B., McClean, J., & Qiu, B. (2015). The Mindanao Current: Mean structure and connectivity. Oceanography, 28, 34–45. https://doi.org/10.1175/1520-0442(1998)011<0676:titatg>2.0.co;2
Schönau, M. C., Wijesekera, H. W., Teague, W. J., Colin, P. L., Gopalakrishnan, G., Rudnick, D. L., et al. (2019). The end of an El Niño: A view from Palau. Oceanography, 32(4), 32–45. https://doi.org/10.5670/oceanog.2019.409
Schramek, T. A., Cornuelle, B. D., Gopalakrishnan, G., Colin, P. L., Rowley, S. J., Merrifield, M. A., et al. (2019). Tropical western Pacific thermal structure and its relationship to ocean surface variables: A numerical state estimate and forereef temperature records. Oceanography, 32(4), 156–163. https://doi.org/10.5670/oceanog.2019.421
Stammer, D., Wunsch, C., Giering, R., Eckert, C., Heimbach, P., Marotzke, J., et al. (2002). Global ocean circulation during 1992–1997, estimated from ocean observations and a general circulation model. Journal of Geophysical Research, 107. https://doi.org/10.1029/2001JC000888
Talley, L. D. (1993). Distribution and formation of North Pacific intermediate water. Journal of Physical Oceanography, 23, 517–537.
Todd, R. E., Rudnick, D. L., Mazloff, M. R., Davis, R. E., & Cornuelle, B. D. (2011). Poleward flows in the southern California Current System: Glider observations and numerical simulation. Journal of Geophysical Research, 116, C02026. https://doi.org/10.1175/1520-0485(1993)023<0517:dafonp>2.0.co;2
Toole, J. M., Zou, E., & Millard, R. C. (1988). On the circulation of the upper waters in the western equatorial Pacific Ocean. Deep-Sea Research Part I: Oceanographic Research Papers, 35, 1451–1482. https://doi.org/10.1016/0198-0149(88)90097-0
Tozuka, T., Kagimoto, T., & Masumoto, Y. (2002). Simulated multiscale variations in the western tropical Pacific: The Mindanao Dome revisited. Journal of Physical Oceanography, 32, 1338–1359. https://doi.org/10.1175/1520-0485(2002)032<1338:SMVITW>2.0.CO;2
Tsuchiya, M. (1968). Upper waters of the intertropical Pacific Ocean. Johns Hopkins Oceanographic Studies, 4, 50.
Tsuchiya, M., Lukas, R., Fine, R. A., Firing, E., & Lindstrom, E. (1989). Source waters of the Pacific Equatorial Undercurrent. Progress in Oceanography, 23, 101–147. https://doi.org/10.1016/0079-6611(89)90012-8
Ueki, I., Kashino, Y., & Kuroda, Y. (2003). Observation of current variations off the New Guinea coast including the 1997–1998 El Niño period and their relationship with Sverdrup transport. Journal of Geophysical Research, 108, 3243. https://doi.org/10.1029/2002JC001611
Wang, B., Wu, R., & Lukas, R. (2000). Annual adjustment of the thermocline in the tropical Pacific Ocean. Journal of Climate, 13(3), 596–616. Retrieved from https://journals.ametsoc.org/view/journals/clim/13/3/1520-0442_2000_013_0596_aaotti_2.0.co_2.xml
Wang, C., Picaut, J., & au, R. (2004). Understanding ENSO physics—A review (pp. 21–48). American Geophysical Union. https://doi.org/10.1175/1520-0442(2000)013<0596:aaotti>2.0.co;2
Wyrtki, K. (1961). Scientific Results of Marine Investigations of the South China Sea and the Gulf of Thailand 1959–1961 (NAGA Report) (Vol. 2).
Wyrtki, K. (1975). El Niño—The dynamic response of the equatorial Pacific Ocean to atmospheric forcing. Journal of Physical Oceanography, 5, 572–584. https://doi.org/10.1175/1520-0485(1975)005%3C0572:ENTDRO%3E2.0.CO;2
Zhang, L., Hui, Y., Qu, T., & Hu, D. (2021). Seasonal variability of subthermocline eddy kinetic energy East of the Philippines. Journal of Physical Oceanography, 51(3), 685–699. Retrieved from https://journals.ametsoc.org/view/journals/phoc/51/3/JPO-D-20-0101.1.xml
Zhang, X., & Clarke, A. J. (2017). On the dynamical relationship between Equatorial Pacific surface currents, zonally averaged equatorial sea level, and El Niño prediction. Journal of Physical Oceanography, 47(2), 323–337. Retrieved from https://journals.ametsoc.org/view/journals/phoc/47/2/jpo-d-16-0193.1.xml
Zhang, L., Wu, J., Wang, F., Hu, S., Wang, Q., Jia, F., et al. (2020). Seasonal and interannual variability of the currents off the new Guinea coast from mooring measurements. Journal of Geophysical Research: Oceans, 125, e2020JC016242. https://doi.org/10.1175/1520-0485(1975)005<0572:entdro>2.0.co;2

Volume127, Issue6

June 2022

e2021JC018213

Mean, Annual, and Interannual Circulation and Volume Transport in the Western Tropical North Pacific From the Western Pacific Ocean State Estimates (WPOSE)

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Mean, Annual, and Interannual Circulation and Volume Transport in the Western Tropical North Pacific From the Western Pacific Ocean State Estimates (WPOSE)

Abstract

Key Points

Plain Language Summary

Open Research

Data Availability Statement

References

References

Related

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RESOURCES

PUBLICATION INFO