Abstract
Pacific Ocean western boundary currents and the interlinked equatorial Pacific circulation system were among the first currents of these types to be explored by pioneering oceanographers. The widely accepted but poorly quantified importance of these currents—in processes such as the El Niño/Southern Oscillation, the Pacific Decadal Oscillation and the Indonesian Throughflow—has triggered renewed interest. Ongoing efforts are seeking to understand the heat and mass balances of the equatorial Pacific, and possible changes associated with greenhouse-gas-induced climate change. Only a concerted international effort will close the observational, theoretical and technical gaps currently limiting a robust answer to these elusive questions.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Nakamura, H., Sampe, T., Tanimoto, Y. & Shimpo, A. Observed associations among stormtracks, jet streams and midlatitude oceanic fronts. AGU Geophys. Monogr. Ser. 147, 329–346 (2004)
Gordon, A. L. Interocean exchange of thermocline water. J. Geophys. Res. 91, 5037–5046 (1986)
Cai, W. et al. More extreme swings of the South Pacific convergence zone due to greenhouse warming. Nature 488, 365–369 (2012)
Ridgway, K. R. & Dunn, J. R. Observational evidence for a Southern Hemisphere oceanic supergyre. Geophys. Res. Lett. 34, L13612 (2007)
Cai, W. Antarctic ozone depletion causes an intensification of the Southern Ocean super-gyre circulation. Geophys. Res. Lett. 33, L03712 (2006)
Speich, S., Blanke, B. & Cai, W. Atlantic meridional overturning circulation and the Southern Hemisphere supergyre. Geophys. Res. Lett. 34, L23614 (2007)
Hu, D. et al. Northwestern Pacific Ocean Circulation and Climate Experiment (NPOCE) Science/Implementation Plan (China Ocean Press, 2011)Details of NPOCE, outlining its goal and scope with a comprehensive literature review on ocean circulation and climate in the northwestern Pacific Ocean.
Ganachaud, A. S. et al. The Southwest Pacific Ocean Circulation and Climate Experiment (SPICE). J. Geophys. Res. 119, 2642–2657 (2014)
Gordon, A. L. et al. The Indonesian Throughflow during 2004–2006 as observed by the INSTANT program. Dyn. Atmos. Oceans 50, 115–128 (2010)
McCreary, J. P. & Lu, P. On the interaction between the subtropical and the equatorial ocean circulations: the subtropical cell. J. Phys. Oceanogr. 24, 466–497 (1994)
Gu, D. F. & Philander, S. G. H. Interdecadal climate fluctuations that depend on exchanges between the tropics and extratropics. Science 275, 805–807 (1997)
Stommel H., Yoshida K., (eds) Kuroshio – Its Physical Aspects (Univ. Tokyo Press, 1972)
Gordon, A. L., Flament, P., Villanoy, C. & Centurioni, L. The nascent Kuroshio of Lamon Bay. J. Geophys. Res. 119, 4251–4263 (2014)
Burrage, D. Naming a western boundary current from Australia to the Solomon Sea. CLIVAR Newsl. Exchanges 58, 28, http://www.clivar.org/node/238 (2012)
Kessler, W. S. & Gourdeau, L. The annual cycle of circulation of the south-west subtropical Pacific, analysed in an ocean GCM. J. Phys. Oceanogr. 37, 1610–1627 (2007)
Lindstrom, E. et al. The western equatorial Pacific Ocean circulation study. Nature 330, 533–537 (1987)
Gordon, A. & Fine, R. Pathways of water between the Pacific and Indian oceans in the Indonesian seas. Nature 379, 146–149 (1996)
Fine, R. A., Lukas, R., Bingham, F. M., Warner, M. J. & Gammon, R. H. The western equatorial Pacific is a water mass crossroads. J. Geophys. Res. 99, 25063–25080 (1994)
Johnson, G., Sloyan, B., Kessler, W. & McTaggart, K. Direct measurements of upper ocean currents and water properties across the tropical Pacific during the 1990s. Prog. Oceanogr. 52, 31–61 (2002)
Gouriou, Y. & Toole, J. Mean circulation of the upper layers of the western equatorial Pacific Ocean. J. Geophys. Res. 98, 22495–22520 (1993)
Hu, D. & Cui, M. The western boundary current of the Pacific and its role in the climate. Chin. J. Oceanology Limnol. 9, 1–14 (1991)
Qu, T., Kagimoto, T. & Yamagata, T. A subsurface countercurrent along the east coast of Luzon. Deep Sea Res. Part I 44, 413–423 (1997)
Hu, D. et al. Direct measurements of the Luzon Undercurrent. J. Phys. Oceanogr. 43, 1417–1425 (2013)
Lukas, R. et al. Observations of the Mindanao Current during the Western Equatorial Pacific Ocean Circulation study (WEPOCS). J. Geophys. Res. 96, 7089–7104 (1991)
Qu, T. & Lindstrom, E. J. Northward Intrusion of Antarctic Intermediate Water in the Western Pacific. J. Phys. Oceanogr. 34, 2104–2118 (2004)
Zhang, L., Hu, D., Hu, S., Wang, F. & Yuan, D. Mindanao Current/Undercurrent measured by a subsurface mooring. J. Geophys. Res. Oceans 119, 3617–3628 (2014)Confirms the existence of the Mindanao Undercurrent and reveals its strong 60–80-day variability using observations spanning two years.
Wijffels, S., Firing, E. & Toole, J. The mean structure and variability of the Mindanao Current at 8°N. J. Geophys. Res. 100, 18421–18435 (1995)
Kashino, Y., Ishida, A. & Kuroda, Y. Variability of the Mindanao Current: mooring observation results. Geophys. Res. Lett. 32, L18611 (2005)
Firing, E., Kashino, Y. & Hacker, P. Energetic subthermocline currents observed east of Mindanao. Deep Sea Res. Part II 52, 605–613 (2005)
Kessler, W. S. & Cravatte, S. ENSO and short-term variability of the south equatorial current entering the Coral Sea. J. Phys. Oceanogr. 43, 956–969 (2013)
Davis, R. E., Kessler, W. S. & Sherman, J. T. Gliders measure western boundary current transport from the South Pacific to the equator. J. Phys. Oceanogr. 42, 2001–2013 (2012)
Gasparin, F., Ganachaud, A., Maes, C., Marin, F. & Eldin, G. Oceanic transports through the Solomon Sea: the bend of the New Guinea Coastal Undercurrent. Geophys. Res. Lett. 39, L15608 (2012)A hydrographic survey across the southern Solomon Sea allows a complete estimate of the NGCU transports down to 2,000 m, as well as counter currents, inflows and outflows between the Solomon and Coral Seas.
Qu, T. & Lindstrom, E. A climatological interpretation of the circulation in the western South Pacific. J. Phys. Oceanogr. 32, 2492–2508 (2002)
Qu, T. & Lukas, R. The bifurcation of the North Equatorial Current in the Pacific. J. Phys. Oceanogr. 33, 5–18 (2003)First report of the findings of vertical distribution and seasonal variation of the NEC bifurcation, with strong relevance to seasonal variation of the South China Sea throughflow in the Luzon Strait found by later studies.
Qiu, B. & Lukas, R. Seasonal and interannual variability of the North Equatorial Current, the Mindanao Current and the Kuroshio along the Pacific western boundary. J. Geophys. Res. 101, 12315–12330 (1996)
Ridgway, K. R. Long term trend and decadal variability of the southward penetration of the East Australia Current. Geophys. Res. Lett. 34, L13613 (2007)
Roemmich, D. et al. Decadal spinup of the South Pacific Subtropical Gyre. J. Phys. Oceanogr. 37, 162–173 (2007)
Beal, L. M. On the role of the Agulhas system in ocean circulation and climate. Nature 472, 429–436 (2011)
Qiu, B., Mao, M. & Kashino, Y. Intraseasonal variability in the Indo-Pacific throughflow and the regions surrounding the Indonesian seas. J. Phys. Oceanogr. 29, 1599–1618 (1999)
Kim, Y. et al. Seasonal and interannual variations of the North Equatorial Current bifurcation in a high-resolution OGCM. J. Geophys. Res. 109, C03040 (2004)
Kashino, Y. et al. Observations of the North Equatorial Current, Mindanao Current, and the Kuroshio Current system during the 2006/7 El Niño and 2007/08 La Niña. J. Oceanogr. 65, 325–333 (2009)
Qiu, B. & Chen, S. Interannual-to-decadal variability in the bifurcation of the north equatorial current off the Philippines. J. Phys. Oceanogr. 40, 2525–2538 (2010)Shows a decadal modulation in the characteristics of the NEC bifurcation, which is determined by wind forcing in the 12°–14° N band that contains variability not fully representable by the Niño-3.4 index.
Wu, C.-R. Interannual modulation of the Pacific Decadal Oscillation (PDO) on the low-latitude western North Pacific. Prog. Oceanogr. 110, 49–58 (2013)
Qiu, B., Kessler, W. S. & Chen, S. Source of the 70-day mesoscale eddy variability in the Coral Sea and North Fiji Basin. J. Phys. Oceanogr. 39, 404–420 (2009)
Ueki, I., Kashino, Y. & Kuroda, Y. Observation of current variations off the New Guinea coast including the 1997–1998 El Niño period and their relationship with Sverdrup transport. J. Geophys. Res. 108 (C7). 3243 (2003)
Jin, F. F. An equatorial ocean recharge paradigm for ENSO. Part I: conceptual model. J. Atmos. Sci. 54, 811–829 (1997)
Melet, A., Gourdeau, L., Verron, J. & Djath, B. Solomon Sea circulation and water mass modifications: response at ENSO timescales. Ocean Dyn. 63, 1–19 (2013)
Sprintall, J. et al. The Indonesian seas and their role in the coupled ocean–climate system. Nature Geosci. 7, 487–492 (2014)Reports recent progress in our understanding of oceanography in the Indonesian Seas and their climatic impact through variations with ENSO, focusing on ocean heat content, sea level, winds and precipitation in the tropical Indian Ocean region.
van Sebille, E. et al. Pacific-to-Indian Ocean connectivity: Tasman leakage, Indonesian Throughflow, and the role of ENSO. J. Geophys. Res. Oceans 119, 1365–1382 (2014)
Gordon, A. L. et al. South China Sea throughflow impact on the Indonesian throughflow. Geophys. Res. Lett. 39, L11602 (2012)
Qu, T., Yan, D. & Hideharu, S. South China Sea throughflow: a heat and freshwater conveyor. Geophys. Res. Lett. 33, L23617 (2006)
Hill, K. L., Rintoul, S. R., Ridgway, K. R. & Oke, P. R. Decadal changes in the South Pacific western boundary current system revealed in observations and ocean state estimates. J. Geophys. Res. 116, C01009 (2011)
Vecchi, G. A. et al. Weakening of tropical Pacific atmospheric circulation due to anthropogenic forcing. Nature 441, 73–76 (2006)
Kelly, K. A. et al. Western boundary currents and frontal air–sea interaction: Gulf Stream and Kuroshio Extension. J. Clim. 23, 5644–5667 (2010)
Kwon, Y. O. et al. Role of the Gulf Stream and Kuroshio–Oyashio systems in large-scale atmosphere–ocean interaction: a review. J. Clim. 23, 3249–3281 (2010)
Konda, M. H., Ichikawa, H., Tomita, H. & Cronin, M. F. Surface heat flux variations across the Kuroshio Extension as observed by surface flux buoys. J. Clim. 23, 5206–5221 (2010)
Chelton, D. B., Schlax, M., Freilich, M. & Milliff, R. Satellite measurements reveal persistent small-scale features in ocean winds. Science 303, 978–983 (2004)
Tokinaga, H. et al. Ocean frontal effects on the vertical development of clouds over the western North Pacific: in situ and satellite observations. J. Clim. 22, 4241–4260 (2009)
Hotta, D. & Nakamura, H. On the significance of the sensible heat supply from the ocean in the maintenance of the mean baroclinicity along storm tracks. J. Clim. 24, 3377–3401 (2011)
Wu, C.-R. et al. Air-sea interaction between tropical cyclone Nari and Kuroshio. Geophys. Res. Lett. 35, L12605 (2008)
Sasaki, n., Minobe, S., Asai, T. & Inatsu, M. Influence of the Kuroshio in the East China Sea on the early summer (baiu) rain. J. Clim. 25, 6627–6645 (2012)
Huang, R. & Li, W. Influence of the heat source anomaly over the tropical western Pacific on the subtropical high over East Asia and its physical mechanism. Chinese J. Atmos. Sci. 14, 95–107 (1988)
Feng, J. & Hu, D. How much does heat content of the western tropical Pacific Ocean modulate the South China Sea summer monsoon onset in the last four decades? J. Geophys. Res. Oceans 119, 4029 (2014)
Holland, G. J. Interannual variability of the Australian summer monsoon at Darwin: 1952–82. Mon. Weath. Rev. 114, 594–604 (1986)
Gordon, A. L., Susanto, R. D. & Vranes, K. Cool Indonesian throughflow as a consequence of restricted surface layer flow. Nature 425, 824–828 (2003)Shows that a stronger low-salinity South China Sea throughflow during boreal winter sets up a gradient, which limits the Mindanao Current inflow into the Indonesian Seas and thus leads to cold surface water in the Indonesian Seas.
Seager, R., Kushnir, Y., Naik, N. H., Cane, M. A. & Miller, J. Wind-driven shifts in the latitude of the Kuroshio–Oyashio Extension and generation of SST anomalies on decadal timescales. J. Clim. 14, 4249–4265 (2001)
Lau, N.-C. & Nath, M. J. Impact of ENSO on SST variability in the North Pacific and North Atlantic: seasonal dependence and role of extratropical sea–air coupling. J. Clim. 14, 2846–2866 (2001)
Alexander, M. A. The atmospheric bridge: the influence of ENSO teleconnections on air–sea interaction over the global oceans. J. Clim. 15, 2205–2231 (2002)
Nakamura, H. & Kazmin, A. S. Decadal changes in the North Pacific oceanic frontal zones as revealed in ship and satellite observations. J. Geophys. Res. 108, 3078 (2003)
Taguchi, B. et al. Decadal variability of the Kuroshio Extension: observations and an eddy-resolving model hindcast. J. Clim. 20, 2357–2377 (2007)
Frankignoul, C. & Sennéchael, N. Observed influence of North Pacific SST anomalies on the atmospheric circulation. J. Clim. 20, 592–606 (2007)
Taguchi, B., Nakamura, H., Nonaka, M. & Xie, S.-P. Influences of the Kuroshio/Oyashio Extensions on air–sea heat exchanges and storm-track activity as revealed in regional atmospheric model simulations for the 2003/04 cold season. J. Clim. 22, 6536–6560 (2009)
Taguchi, B., Xie, S.-P., Mitsudera, H. & Kubokawa, A. Response of the Kuroshio Extension to Rossby waves associated with the 1970s climate regime shift in a high-resolution ocean model. J. Clim. 18, 2979–2995 (2005)
Liu, Z. & Alexander, M. Atmospheric bridge, oceanic tunnel and global climatic teleconnections. Rev. Geophys. 45, RG2005 (2007)
Tokinaga, H. et al. Atmospheric sounding over the winter Kuroshio Extension: effect of surface stability on atmospheric boundary layer structure. Geophys. Res. Lett. 33, L04703 (2006)
Norris, J. R. & Leovy, C. B. Interannual variability in stratiform cloudiness and sea surface temperature. J. Clim. 7, 1915–1925 (1994)
Klein, S. A., Hartmann, D. L. & Norris, J. R. On the relationships among low-cloud structure, sea surface temperature and atmospheric circulation in the summertime northeast Pacific. J. Clim. 8, 1140–1155 (1995)
Park, S., Alexander, M. A. & Deser, C. The impact of cloud radiative feedback, remote ENSO forcing, and entrainment on the persistence of North Pacific sea surface temperature anomalies. J. Clim. 19, 6243–6261 (2006)
Alexander, M. A. & Deser, C. A mechanism for the recurrence of wintertime midlatitude SST anomalies. J. Phys. Oceanogr. 25, 122–137 (1995)
Sugimoto, S. & Hanawa, K. Remote reemergence areas of winter sea surface temperature anomalies in the North Pacific. Geophys. Res. Lett. 32, L01606 (2005)
Nakamura, H. & Yamagata, T. in Beyond El Nino: Decadal and Interdecadal Climate Variability (ed. Navarra, A. ) 49–72 (Springer, 1999)
Sprintall, J., Roemmich, D., Stanton, B. & Bailey, R. Regional climate variability and ocean heat transport in the southwest Pacific Ocean. J. Geophys. Res. 100, 15865–15871 (1995)
Shi, G., Ribbe, J., Cai, W. & Cowan, T. An interpretation of Australian rainfall projections. Geophys. Res. Lett. 35, L02702 (2008)
Godfrey, S. The effect of the Indonesian Throughflow on ocean circulation and heat exchange with the atmosphere: A review. J. Geophys. Res. Oceans 101, 12217–12237 (1996)
Vranes, K., Gordon, A. L. & Field, A. The heat transport of the Indonesian throughflow and implications for the Indian Ocean heat budget. Deep Sea Res. Part II 49, 1391–1410 (2002)
Gordon, A. L. Oceanography of the Indonesian Seas and their throughflow. Oceanography (Wash. D.C.) 18, 14–27 (2005)
Song, Q., Gordon, A. L. & Visbeck, M. Spreading of the Indonesian throughflow in the Indian Ocean. J. Phys. Oceanogr. 34, 772–792 (2004)
Wu, L. et al. Enhanced warming over the global subtropical western boundary current. Nature Clim. Change 2, 161–166 (2012)Demonstrates synchronized enhanced warming along subtropical WBCs and emphasizes the important roles played by the WBCs in global climate change.
Zhai, F., Hu, D., Wang, Q. & Wang, F. Long-term trend of Pacific South Equatorial Current bifurcation. Geophys. Res. Lett. 41, 3172–3180 (2014)
Chen, Z. & Wu, L. Long-term change of the Pacific North Equatorial Current bifurcation in SODA. J. Geophys. Res. 117, C06016 (2012)
Cai, W. & Cowan, T. Trends in Southern Hemisphere circulation in IPCC AR4 models over 1950–1999: ozone-depletion vs greenhouse forcing. J. Clim. 20, 681–693 (2007)
Cai, W., Shi, G., Cowan, T., Bi, D. & Ribbe, J. The response of the Southern Annular Mode, the East Australian Current, and the southern mid-latitude ocean circulation to global warming. Geophys. Res. Lett. 32, L23706 (2005)
Thompson, D. W. J. et al. Signatures of the Antarctic ozone hole in Southern Hemisphere surface climate change. Nature Geosci. 4, 741–749 (2011)
Wang, G., Cai, W. & Purich, A. Trends in Southern Hemisphere wind driven circulation in CMIP5 models over the 21st century: ozone recovery versus greenhouse forcing. J. Geophys. Res. Oceans 119, 2974–2986 (2014)
Ganachaud, A. et al. Projected changes in the tropical Pacific Ocean of importance to tuna fisheries. Clim. Change 119, 163–179 (2013)Presents global warming projections showing a shift in the Pacific winds and surface temperatures that affect oceanic currents and vertical ocean structure, enhancing stratification and increasing the extent of the warm pool with consequences for tuna habitat.
Sen Gupta, A., Ganachaud, A., McGregor, S., Brown, J. N. & Muir, L. Drivers of the projected changes to the Pacific Ocean equatorial circulation. Geophys. Res. Lett. 39, L09605 (2012)
Grenier, M., Jeandel, C. & Cravatte, S. From the subtropics to the equator in the Southwest Pacific: continental material fluxes quantified using neodymium data along modelled thermocline water pathways. J. Geophys. Res. Oceans 119, 3948–3966 (2014)
Gregory, J. M. et al. A model intercomparison of changes in the Atlantic thermohaline circulation in response to increasing atmospheric CO2 concentration. Geophys. Res. Lett. 32, L12703 (2005)
Li, W., Li, L., Ting, M. & Liu, Y. Intensification of Northern Hemisphere subtropical highs in a warming climate. Nature Geosci. 5, 830–834 (2012)
Oliver, E. C. J. & Holbrook, N. J. Extending our understanding of South Pacific gyre “spin-up”: modeling the East Australian Current in a future climate. J. Geophys. Res. Oceans 119, 2788–2805 (2014)Shows that an increase in the EAC extension of 4–5 Sv by 2060 simulated by a high-resolution model closely matches results from a low-resolution climate model.
Acknowledgements
W.C. and G.W. are supported by the Australian Climate Change Science Program, a CSIRO Office of the Chief Executive Science Leader award, and CSIRO Office of the Chief Executive postdoctoral awards. L.W., Z.C. and X.L. are supported by projects (41130859,41490640, 41306001) of the National Science Foundation of China (NSFC), and a project (2013CB956200) of the National Basic Research Program of China (MOST). D.H. is supported by CAS Program XDA 11010101, and NSFC Grants 41330963 and 41421005. S.H. is supported by NSFC Grant 41406016. Q.W. is supported by MOST Grant 2013CB956202. F.W. is supported by MOST Grant 2012CB417401 and NSFC/Shangdong Grant U1406401, A.G. is supported by CNRS/INSU/LEFE project MoorSPICE. This is PMEL Contribution Number 4207, and Lamont-Doherty Earth Observatory Contribution Number 7875. J.S. is supported by the National Aeronautics and Space Administration (NASA) under award no. NNX13AO38G. Y.K. is supported by the Tropical Ocean Climate Study of Japan Agency for Marine-Earth Science and Technology. This is a contribution to the CLIVAR SPICE and NPOCE programmes. We thank A. Purich and T. Cowan for their comments before submission. We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, and we thank the climate modelling groups for producing and making available their model output. The US Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led the development of software infrastructure in partnership with the Global Organization for Earth System Science Portals.
Author information
Authors and Affiliations
Contributions
D.H., L.W. and W.C. conceived the study. L.W., W.C. and D.H. determined the scope. W.C. wrote the draft of the paper and finalized the manuscript with help from G.W. A.S.G. conducted model output analysis for future projections and plotted Fig. 5. A.G., A.S.G. and W.C. constructed the schematic of Figs 1 and 3. Z.C. generated Fig. 4. All authors contributed to interpreting results, discussion of the associated dynamics and improvement of this paper.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Rights and permissions
About this article
Cite this article
Hu, D., Wu, L., Cai, W. et al. Pacific western boundary currents and their roles in climate. Nature 522, 299–308 (2015). https://doi.org/10.1038/nature14504
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nature14504
This article is cited by
-
Mechanisms of projected sea-level trends and variability in the Southeast Asia region based on MPI-ESM-ER
Climate Dynamics (2024)
-
Projected Atlantic overturning slow-down is to be compensated by a strengthened South Atlantic subtropical gyre
Communications Earth & Environment (2023)
-
The seas around China in a warming climate
Nature Reviews Earth & Environment (2023)
-
Study of coexisting upstream solitary wave packet and downstream wakes induced by Diaoyu Dao and its affiliated islands detected by satellite sun glitter
Acta Oceanologica Sinica (2023)
-
Variation in concentration of dissolved silicate in the Eastern Philippine deep sea
Journal of Oceanology and Limnology (2023)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.