Editorial Type:
Article
Article Type:
Research Article

Subduction of South Pacific Tropical Water and Its Equatorward Pathways as Shown by a Simulated Passive Tracer

Tangdong Qu International Pacific Research Center, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, Honolulu, Hawaii

Search for other papers by Tangdong Qu in
Current site
Google Scholar
PubMed Close
,
Shan Gao International Pacific Research Center, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, Honolulu, Hawaii

Search for other papers by Shan Gao in
Current site
Google Scholar
PubMed Close
, and
Rana A. Fine Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida

Search for other papers by Rana A. Fine in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Aug 2013
DOI:
https://doi.org/10.1175/JPO-D-12-0180.1
Page(s):
1551–1565
Restricted access

Abstract

This study investigates the subduction of South Pacific Tropical Water (SPTW) and its equatorward pathways using a simulated passive tracer of the consortium Estimating the Circulation & Climate of the Ocean (ECCO). The results show that approximately 5.8 Sv (1 Sv ≡ 106 m3 s−1) of the SPTW is formed in the subtropical South Pacific Ocean within the density range between 24.0 and 25.0 kg m−3, of which about 87% is due to vertical pumping and 13% is due to lateral induction, comparing reasonably well with estimates from climatological data. Once subducted, most SPTW spreads in the subtropical South Pacific. Because of the presence of mixing, some portion of the water is transformed, and its tracer-weighted density steadily increases from an initial value of 24.4 to nearly 25.0 kg m−3 after 13 years of integration. Approximately 42% of the water makes its way into the equatorial Pacific, either through the western boundary or interior pathway. The two equatorward pathways are essentially of equal importance. A large (~70%) portion of the SPTW entering the equatorial region resurfaces in the central equatorial Pacific. The potential impacts of the resurfacing SPTW on the equatorial thermocline and surface stratification are discussed.

School of Ocean and Earth Science and Technology Contribution Number 8934 and International Pacific Research Center Contribution Number IPRC-982.

Current affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.

Corresponding author address: Dr. Tangdong Qu, International Pacific Research Center, SOEST, University of Hawaii at Manoa, 1680 East-West Road, Honolulu, HI 96822. E-mail: tangdong@hawaii.edu

Abstract

This study investigates the subduction of South Pacific Tropical Water (SPTW) and its equatorward pathways using a simulated passive tracer of the consortium Estimating the Circulation & Climate of the Ocean (ECCO). The results show that approximately 5.8 Sv (1 Sv ≡ 106 m3 s−1) of the SPTW is formed in the subtropical South Pacific Ocean within the density range between 24.0 and 25.0 kg m−3, of which about 87% is due to vertical pumping and 13% is due to lateral induction, comparing reasonably well with estimates from climatological data. Once subducted, most SPTW spreads in the subtropical South Pacific. Because of the presence of mixing, some portion of the water is transformed, and its tracer-weighted density steadily increases from an initial value of 24.4 to nearly 25.0 kg m−3 after 13 years of integration. Approximately 42% of the water makes its way into the equatorial Pacific, either through the western boundary or interior pathway. The two equatorward pathways are essentially of equal importance. A large (~70%) portion of the SPTW entering the equatorial region resurfaces in the central equatorial Pacific. The potential impacts of the resurfacing SPTW on the equatorial thermocline and surface stratification are discussed.

School of Ocean and Earth Science and Technology Contribution Number 8934 and International Pacific Research Center Contribution Number IPRC-982.

Current affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.

Corresponding author address: Dr. Tangdong Qu, International Pacific Research Center, SOEST, University of Hawaii at Manoa, 1680 East-West Road, Honolulu, HI 96822. E-mail: tangdong@hawaii.edu
Save
Cover Journal of Physical Oceanography
Journal of Physical Oceanography

  • Adler, R. F., and Coauthors, 2003: The Version-2 Global Precipitation Climatology Project (GPCP) monthly precipitation analysis (1979–present). J. Hydrometeor., 4, 1147–1167.

    • Search Google Scholar
    • Export Citation

  • Barnier, B., L. Siefridt, and P. Marchesiello, 1995: Thermal forcing for a global ocean circulation model using a three-year climatology of ECMWF analysis. J. Mar. Syst., 6, 363–380.

    • Search Google Scholar
    • Export Citation

  • Delcroix, T., and M. J. McPhaden, 2002: Interannual sea surface salinity and temperature changes in the western Pacific warm pool during 1992–2000. J. Geophys. Res., 107, 8002, doi:10.1029/2001JC000862.

    • Search Google Scholar
    • Export Citation

  • Fine, R. A., R. Lukas, F. M. Bingham, M. J. Warner, and R. H. Gammon, 1994: The western equatorial Pacific: A water mass crossroads. J. Geophys. Res., 99 (C12), 25 063–25 080.

    • Search Google Scholar
    • Export Citation

  • Fine, R. A., K. A. Maillet, K. F. Sullivan, and D. Willey, 2001: Circulation and ventilation flux of the Pacific Ocean. J. Geophys. Res., 106 (C10), 22 159–22 178.

    • Search Google Scholar
    • Export Citation

  • Fukumori, I., T. Lee, B. Cheng, and D. Menemnlis, 2004: The origin, pathway, and destination of Niño-3 water estimated by a simulated passive tracer and its adjoint. J. Phys. Oceanogr., 34, 582–604.

    • Search Google Scholar
    • Export Citation

  • Gao, S., T. Qu, and I. Fukumori, 2011: Effects of mixing on the subduction of South Pacific waters. Dyn. Atmos. Oceans, 51, 45–54.

  • Gent, P. R., and J. C. McWilliams, 1990: Isopycnal mixing in ocean circulation models. J. Phys. Oceanogr., 20, 150–155.

  • Grenier, M., S. Cravatte, B. Blanke, C. Menkes, A. Koch-Larrouy, F. Durand, A. Melet, and C. Jeandel, 2011: From the western boundary currents to the Pacific Equatorial Undercurrent: Modeled pathways and water mass evolutions. J. Geophys. Res., 116, C12044, doi:10.1029/2011JC007477.

    • Search Google Scholar
    • Export Citation

  • Gu, D., and S. G. H. Philander, 1997: Interdecadal climate fluctuations that depend on exchange between the tropics and extratropics. Science, 275, 805–807.

    • Search Google Scholar
    • Export Citation

  • Hanawa, K., and L. D. Talley, 2001: Mode waters. Ocean Circulation and Climate, G. Sieldler, J. Church, and J. Gould, Eds., Academic Press, 373–386.

  • Huang, R. X., and B. Qiu, 1998: The structure of the wind-driven circulation in the subtropical South Pacific Ocean. J. Phys. Oceanogr., 28, 1173–1186.

    • Search Google Scholar
    • Export Citation

  • Johnson, G. C., and M. J. McPhaden, 1999: Interior pycnocline flow from the subtropical to the equatorial Pacific Ocean. J. Phys. Oceanogr.,29, 3073–3089.

  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77, 437–371.

  • Kessler, W. S., 2006: The circulation of the eastern tropical Pacific: A review. Prog. Oceanogr., 69, 181–217.

  • Kessler, W. S., and B. A. Taft, 1987: Dynamic heights and zonal geostrophic transports in the central tropical Pacific during 1979–1984. J. Phys. Oceanogr., 17, 97–122.

    • Search Google Scholar
    • Export Citation

  • Large, W. G., J. C. McWilliams, and S. C. Doney, 1994: Oceanic vertical mixing: A review and a model with a nonlocal boundary-layer parameterization. Rev. Geophys., 32, 363–403.

    • Search Google Scholar
    • Export Citation

  • Lindstrom, E., R. Lukas, R. Fine, E. Firing, S. J. Godfrey, G. Meyers, and M. Tsuchiya, 1987: The western equatorial Pacific Ocean circulation study. Nature, 330, 533–537.

    • Search Google Scholar
    • Export Citation

  • Lukas, R., and E. Lindstrom, 1991: The mixed layer of the western equatorial Pacific Ocean. J. Geophys. Res., 96, 3343–3358.

  • Luo, J.-J., and T. Yamagata, 2001: Long-term El Niño–Southern Oscillation (ENSO)-like variation with special emphasis on the South Pacific. J. Geophys. Res., 106 (C10), 22 211–22 227.

    • Search Google Scholar
    • Export Citation

  • Maes, C., 2008: On the ocean salinity stratification observed at the eastern edge of the equatorial Pacific warm pool. J. Geophys. Res., 113, C03027, doi:10.1029/2007JC004297.

    • Search Google Scholar
    • Export Citation

  • Marshall, J. C., 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. J. Geophys. Res., 102 (C3), 5753–5766.

    • Search Google Scholar
    • Export Citation

  • McCreary, J. P., and P. Lu, 1994: On the interaction between the subtropical and the equatorial oceans: The subtropical cell. J. Phys. Oceanogr., 24, 466–497.

    • Search Google Scholar
    • Export Citation

  • McPhaden, M. J., and J. Picaut, 1990: El Niño–Southern Oscillation displacement of the western equatorial Pacific warm pool. Science, 250, 1385–1388.

    • Search Google Scholar
    • Export Citation

  • McPhaden, M. J., and D. Zhang, 2002: Slowdown of the meridional overturning circulation in the upper Pacific Ocean. Nature, 415, 603–608.

    • Search Google Scholar
    • Export Citation

  • McPhaden, M. J., S. E. Zebiak, and M. H. Glantz, 2006: ENSO as an integrating concept in earth. Science, 314, 1740–1745.

  • O'Connor, B. M., R. A. Fine, K. A. Maillet, and D. B. Olson, 2002: Formation rates of subtropical underwater in the Pacific Ocean. Deep-Sea Res., 49, 1571–1590.

    • Search Google Scholar
    • Export Citation

  • O'Connor, B. M., R. A. Fine, and D. B. Olson, 2005: A global comparison of subtropical underwater formation rate. Deep-Sea Res., 52, 1569–1590.

    • Search Google Scholar
    • Export Citation

  • Palmer, T. N., and D. A. Mansfield, 1984: Response of two atmospheric general circulation models to sea surface temperature anomalies in the tropical east and west Pacific. Nature, 310, 483.

    • Search Google Scholar
    • Export Citation

  • Picaut, J., M. Loualalen, C. Menkes, T. Delcroix, and M. J. McPhaden, 1996: Mechanism of the zonal displacement of the Pacific warm pool: Implications for ENSO. Science, 274, 1486–1489.

    • Search Google Scholar
    • Export Citation

  • Qu, T., H. Mitsudera, and T. Yamagata, 1999: A climatology of the circulation and water mass distribution near the Philippine coast. J. Phys. Oceanogr., 29, 1488–1505.

    • Search Google Scholar
    • Export Citation

  • Qu, T., S. Gao, I. Fukumori, R. A. Fine, and E. J. Lindstrom, 2008: Subduction of South Pacific waters. Geophys. Res. Lett., 35, L02610, doi:10.1029/2007GL032605.

    • Search Google Scholar
    • Export Citation

  • Qu, T., S. Gao, I. Fukumori, R. A. Fine, and E. J. Lindstrom, 2009: Origin and pathway of equatorial 13°C Water in the Pacific identified by a simulated passive tracer and its adjoint. J. Phys. Oceanogr., 39, 1836–1853.

    • Search Google Scholar
    • Export Citation

  • Redi, M., 1982: Oceanic isopycnal mixing by coordinate rotation. J. Phys. Oceanogr., 12, 1154–1158.

  • Reynolds, R. W., and T. M. Smith, 1994: Improved global sea surface temperature analyses using optimum interpolation. J. Climate, 7, 929–948.

    • Search Google Scholar
    • Export Citation

  • Rodgers, K. B., B. Blanke, G. Mades, O. Aumont, P. Ciais, and J.-C. Dutay, 2003: Extratropical sources of equatorial Pacific upwelling in an OGCM. Geophys. Res. Lett., 30, 1084, doi:10.1029/2002GL016003.

    • Search Google Scholar
    • Export Citation

  • Roemmich, D., and B. Cornuelle, 1992: The subtropical mode waters of the South Pacific Ocean. J. Phys. Oceanogr., 22, 1178–1187.

  • Singh, A., T. Delcroix, and S. Cravatte, 2011: Contrasting the flavors of El Niño–Southern Oscillation using sea surface salinity observations. J. Geophys. Res., 116, C06016, doi:10.1029/2010JC006862.

    • Search Google Scholar
    • Export Citation

  • Slutz, R. J., S. J. Lubker, J. D. Hiscox, S. D. Woodruff, R. L. Jenne, D. H. Joseph, P. M. Steurer, and J. D. Elms, 1985: Comprehensive ocean–atmosphere data set; Release 1. NOAA Environmental Research Laboratories, Climate Research Program Rep. NTIS PB86–105723, 268 pp.

  • Tsuchiya, M., and L. D. Talley, 1996: Water property distributions along an eastern Pacific hydrographic section at 135°W. J. Mar. Res., 54, 541–564.

    • Search Google Scholar
    • Export Citation

  • Tsuchiya, M., R. Lukas, R. A. Fine, E. Firing, and E. Lindstrom, 1989: Source waters of the Pacific Equatorial Undercurrent. Prog. Oceanogr.,23, 101–147.

  • White, W. B., and D. R. Cayan, 1998: Quasi-periodicity and global symmetries in interdecadal upper ocean temperature variability. J. Geophys. Res., 103 (C10), 21 335–21 354.

    • Search Google Scholar
    • Export Citation

  • Yu, L., 2007: Global variations in oceanic evaporation (1958–2005): The role of the changing wind speed. J. Climate, 20, 5376–5390.

  • Zhang, R.-H., L. M. Rothstein, and A. J. Busalacchi, 1998: Origin of upper-ocean warming and El Niño change on decadal scales in the tropical Pacific Ocean. Nature, 391, 879–883.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 1812 1089 39
PDF Downloads 616 129 12