• Adcroft, A. J., J.-M. Campin, C. N. Hill, and J. Marshall, 2004: Implementation of an atmosphere–ocean general circulation model on the expanded spherical cube. Mon. Wea. Rev., 132, 28452863.

    • Search Google Scholar
    • Export Citation
  • Adler, R. F., and Coauthors, 2003: The version 2 Global Precipitation Climatology Project (GPCP) monthly precipitation analysis (1979–Present). J. Hydrometeor., 4, 11471167.

    • Search Google Scholar
    • Export Citation
  • Alexander, M., 1992: Midlatitude atmosphere–ocean interaction during El Niño. Part I: The North Pacific Ocean. J. Climate, 5, 944958.

    • Search Google Scholar
    • Export Citation
  • Bingham, F. M., 1992: The formation and spreading of subtropical mode water in the North Pacific. J. Geophys. Res., 97, 11 17711 189.

    • Search Google Scholar
    • Export Citation
  • Chen, J., T. Qu, Y. Sasaki, and N. Schneider, 2010: Anti-correlated variability in subduction rate of the western and eastern North Pacific Oceans. J. Geophys. Res. Lett., 37, L23608, doi:10.1029/2010GL045239.

    • Search Google Scholar
    • Export Citation
  • Cushman-Roisin, B., 1987: Dynamics of the oceanic surface mixed layer. Hawaii Institute of Geophysics Special Publications, P. Muller and D. Henderson, Eds., Hawaii Institute of Geophysics, 181–196.

    • Search Google Scholar
    • Export Citation
  • Deser, C., and M. L. Blackmon, 1995: On the relationship between tropical and North Pacific sea surface temperature variations. J. Climate, 8, 16771680.

    • Search Google Scholar
    • Export Citation
  • Deser, C., M. A. Alexander, and M. S. Timlin, 1999: Evidence for a wind-driven intensification of the Kuroshio Current extension from the 1970s to the 1980s. J. Climate, 12, 16971706.

    • Search Google Scholar
    • Export Citation
  • Dewar, W. K., R. M. Samelson, and G. K. Vallis, 2005: The ventilated pool: A model of subtropical mode water. J. Phys. Oceanogr., 35, 137150.

    • Search Google Scholar
    • Export Citation
  • Fox-Kemper, B., and D. Menemenlis, 2008: Can large eddy simulation techniques improve mesoscale rich ocean models? Ocean Modeling in an Eddying Regime, Geophys. Monogr., Vol. 177, Amer. Geophys. Union, 319–388.

    • Search Google Scholar
    • Export Citation
  • Gibson, J. K., P. Kållberg, S. Uppala, A. Hernandez, A. Nomura, and E. Serrano, 1997: ERA description. ERA Project Rep. Series 1, ECMWF, 18 pp.

    • Search Google Scholar
    • Export Citation
  • Hanawa, K., and J. Kamada, 2001: Variability of core layer temperature (CLT) of the North Pacific Subtropical Mode Water. Geophys. Res. Lett., 28, 22292232.

    • Search Google Scholar
    • Export Citation
  • Hosoda, S., S.-P. Xie, K. Takeuchi, and M. Nonaka, 2004: Interdecadal temperature variations in the North Pacific Central Mode Water simulated by an OGCM. J. Oceanogr., 60, 865877.

    • Search Google Scholar
    • Export Citation
  • Jenkins, W. J., 1982: On the climate of a subtropical ocean gyre: Decadal time scale variations in water mass renewal in the Sargasso Sea. J. Mar. Res., 40 (Suppl.), 265290.

    • Search Google Scholar
    • Export Citation
  • Kelly, K. A., and S. Dong, 2004: The relationship of western boundary current heat transport and storage to mid-latitude ocean–atmosphere interaction. Earth’s Climate: The Ocean–Atmosphere Interaction, Geophys. Monogr., Vol. 147, Amer. Geophys. Union, 347–363.

    • Search Google Scholar
    • Export Citation
  • Kubokawa, A., 1999: Ventilated thermocline strongly affected by a deep mixed layer: A theory for subtropical countercurrent. J. Phys. Oceanogr., 29, 13141333.

    • Search Google Scholar
    • Export Citation
  • Kwon, Y.-O., 2003: Observation of general circulation and water mass variability in the North Atlantic Subtropical Mode Water region. Ph.D. thesis, University of Washington, 161 pp.

  • Kwon, Y.-O., and S. C. Riser, 2004: North Atlantic Subtropical Mode Water: A history of ocean–atmosphere interaction 1961–2000. Geophys. Res. Lett., 31, L19307, doi:10.1029/2004GL021116.

    • Search Google Scholar
    • Export Citation
  • Ladd, C., and L. Thompson, 2001: Water mass formation in an isopycnal model of the North Pacific. J. Phys. Oceanogr., 31, 15171537.

  • Ladd, C., and L. Thompson, 2002: Decadal variability of North Pacific Central Mode Water. J. Phys. Oceanogr., 32, 28702881.

  • Large, W. G., and S. Pond, 1982: Sensible and latent heat flux measurement over the ocean. J. Phys. Oceanogr., 12, 464482.

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

    • Search Google Scholar
    • Export Citation
  • Large, W. G., J. Morzel, and G. Crawford, 1995: Accounting for surface wave distortion of the marine wind profile in low-level ocean storms wind measurements. J. Phys. Oceanogr., 25, 29592971.

    • Search Google Scholar
    • Export Citation
  • Latif, M., and T. P. Barnett, 1994: Causes of decadal climate variability over the North Pacific and North America. Science, 266, 634637.

    • Search Google Scholar
    • Export Citation
  • Luksch, U., and H. von Storch, 1992: Modeling the low-frequency sea surface temperature variability in the North Pacific. J. Climate, 5, 893906.

    • Search Google Scholar
    • Export Citation
  • Luo, Y., Q. Liu, and L. M. Rothstein, 2009: Simulated response of North Pacific Mode Waters to global warming. Geophys. Res. Lett., 36, L23609, doi:10.1029/2009GL040906.

    • Search Google Scholar
    • Export Citation
  • 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. J. Geophys. Res., 102, 5753.

    • Search Google Scholar
    • Export Citation
  • Masuzawa, J., 1969: Subtropical mode water. Deep-Sea Res., 16, 463472.

  • McCartney, M., 1982: The subtropical recirculation of mode waters. J. Mar. Res., 40 (Suppl.), 427464.

  • Menemenlis, D., I. Fukumori, and T. Lee, 2005a: Using Green’s functions to calibrate an ocean general circulation model. Mon. Wea. Rev., 133, 12241240.

    • Search Google Scholar
    • Export Citation
  • Menemenlis, D., and Coauthors, 2005b: NASA supercomputer improves prospects for ocean climate research. Eos, Trans. Amer. Geophys. Union, 86, 89, doi:10.1029/2005EO090002.

    • Search Google Scholar
    • Export Citation
  • Menemenlis, D., P. Heimbach, C. Hill, T. Lee, A. Nguyen, M. Schodlok, and H. Zhang, 2008: ECCO2: High-resolution global ocean and sea ice data synthesis. Mercator Ocean Quarterly Newsletter, Vol. 31, Mercator Ocean, Agne, France, 13–21.

    • Search Google Scholar
    • Export Citation
  • Miller, A. J., D. R. Cayan, T. P. Barnett, N. E. Graham, and J. M. Oberhuber, 1994: Interdecadal variability of the Pacific Ocean: Model response to observed heat flux and wind stress anomalies. Climate Dyn., 9, 287302.

    • Search Google Scholar
    • Export Citation
  • Oka, E., 2009: Seasonal and Interannual Variation of North Pacific Subtropical Mode Water in 2003–06. J. Oceanogr., 65, 151164.

  • Oka, E., and T. Suga, 2003: Formation region of North Pacific Subtropical Mode Water in the late winter of 2003. Geophys. Res. Lett., 30, 2205, doi:10.1029/2003GL018581.

    • Search Google Scholar
    • Export Citation
  • Qiu, B., and S. Chen, 2006: Decadal variability in the formation of the North Pacific Subtropical Mode Water: Oceanic versus atmospheric control. J. Phys. Oceanogr., 36, 13651380.

    • Search Google Scholar
    • Export Citation
  • Qiu, B., P. Hacker, S. Chen, K. A. Donohue, D. R. Watts, H. Mitsudera, N. G. Hogg, and S. R. Jayne, 2006: Observations of the subtropical mode water evolution from the Kuroshio Extension system study. J. Phys. Oceanogr., 36, 457473.

    • Search Google Scholar
    • Export Citation
  • Qiu, B., S. Chen, and P. Hacker, 2007: Effect of mesoscale eddies on subtropical mode water variability from the Kuroshio Extension System Study (KESS). J. Phys. Oceanogr., 37, 9821000.

    • Search Google Scholar
    • Export Citation
  • Qu, T., and J. Chen, 2009: A North Pacific decadal variability in subduction rate. Geophys. Res. Lett., 36, L22602, doi:10.1029/2009GL040914.

    • Search Google Scholar
    • Export Citation
  • Qu, T., S.-P. Xie, H. Mitsudera, and A. Ishida, 2002: Subduction of the North Pacific Mode Waters in a global high-resolution GCM. J. Phys. Oceanogr., 32, 746763.

    • Search Google Scholar
    • Export Citation
  • Rainville, L., S. R. Jayne, J. L. McClean, and M. E. Maltrud, 2007: Formation of subtropical mode water in a high-resolution ocean simulation of the Kuroshio Extension region. Ocean Modell., 17, 338356.

    • Search Google Scholar
    • Export Citation
  • Roemmich, D., J. Gilson, J. Willis, P. Sutton, and K. Ridgway, 2005: Closing the time-varying mass and heat budgets for large ocean areas: The Tasman box. J. Climate, 18, 23302343.

    • Search Google Scholar
    • Export Citation
  • Schneider, N., and A. Miller, 2001: Predicting western North Pacific Ocean climate. J. Climate, 14, 39974002.

  • Speer, K., and E. Tziperman, 1990: Convection from a source in an ocean basin. Deep-Sea Res., 37, 431446.

  • Sprinthall, R. C., 1990: Basic Statistical Analysis. 3rd ed. Prentice Hall, 468 pp.

  • Suga, T., and K. Hanawa, 1990: The mixed-layer climatology in the northwestern part of the North Pacific subtropical gyre and the formation area of the subtropical mode water. J. Mar. Res., 48, 543566.

    • Search Google Scholar
    • Export Citation
  • Suga, T., and K. Hanawa, 1995: The subtropical mode water circulation in the North Pacific. J. Phys. Oceanogr., 25, 958970.

  • Taguchi, B., S.-P. Xie, H. Mitsudera, and A. Kubokawa, 2005: Response of the Kuroshio Extension to Rossby waves associated with the 1970s climate regime shift in a high-resolution ocean model. J. Climate, 18, 29792995.

    • Search Google Scholar
    • Export Citation
  • Taneda, T., T. Suga, and K. Hanawa, 2000: Subtropical mode water variation in the northwestern part of the North Pacific subtropical gyre. J. Geophys. Res., 105, 19 59119 598.

    • Search Google Scholar
    • Export Citation
  • Tsujino, H., and T. Yasuda, 2004: Formation and circulation of the mode waters of the North Pacific in a high-resolution GCM. J. Phys. Oceanogr., 34, 399415.

    • Search Google Scholar
    • Export Citation
  • Uehara, H., T. Suga, K. Hanawa, and N. Shikama, 2003: A role of eddies in formation and transport of North Pacific Subtropical mode water. Geophys. Res. Lett., 30, 1705, doi:10.1029/2003GL017542.

    • Search Google Scholar
    • Export Citation
  • Uppala, S. M., and Coauthors, 2005: The ERA-40 Re-Analysis. Quart. J. Roy. Meteor. Soc., 131, 29613012.

  • Williams, R. G., 1991: The Role of the mixed layer in setting the potential vorticity of the main thermocline. J. Phys. Oceanogr., 21, 18031814.

    • Search Google Scholar
    • Export Citation
  • Worthington, L. V., 1959: The 18° water in the Sargasso Sea. Deep-Sea Res., 5, 297305.

  • Xie, S.-P., T. Kunitani, A. Kubokawa, M. Nonaka, and S. Hosoda, 2000: Interdecadal thermocline variability in the North Pacific for 1958–1997: A GCM simulation. J. Phys. Oceanogr., 30, 27982813.

    • Search Google Scholar
    • Export Citation
  • Yamanaka, G., H. Ishizaki, M. Hirabara, and I. Ishikawa, 2008: Decadal variability of the Subtropical Front of the western North Pacific in an eddy-resolving ocean general circulation model. J. Geophys. Res., 113, C12027, doi:10.1029/2008JC005002.

    • Search Google Scholar
    • Export Citation
  • Yasuda, T., and K. Hanawa, 1997: Decadal changes in the mode waters in the midlatitude North Pacific. J. Phys. Oceanogr., 27, 858870.

    • Search Google Scholar
    • Export Citation
  • Yasuda, T., and Y. Kitamura, 2003: Long-term variability of the North Pacific subtropical mode water in response to the spin-up of the subtropical gyre. J. Oceanogr., 9, 279290.

    • Search Google Scholar
    • Export Citation
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Numerical Investigations of Seasonal and Interannual Variability of North Pacific Subtropical Mode Water and Its Implications for Pacific Climate Variability

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  • 1 Physical Oceanography Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts
  • | 2 Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island
  • | 3 Department of Oceanography, The Florida State University, Tallahassee, Florida
  • | 4 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
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Abstract

North Pacific Subtropical Mode Water (NPSTMW) is an essential feature of the North Pacific subtropical gyre imparting significant influence on regional SST evolution on seasonal and longer time scales and, as such, is an important component of basin-scale North Pacific climate variability. This study examines the seasonal-to-interannual variability of NPSTMW, the physical processes responsible for this variability, and the connections between NPSTMW and basin-scale climate signals using an eddy-permitting 1979–2006 ocean simulation made available by the Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2). The monthly mean seasonal cycle of NPSTMW in the simulation exhibits three distinct phases: (i) formation during November–March, (ii) isolation during March–June, and (iii) dissipation during June–November—each corresponding to significant changes in upper-ocean structure. An interannual signal is also evident in NPSTMW volume and other characteristic properties with volume minima occurring in 1979, 1988, and 1999. This volume variability is correlated with the Pacific decadal oscillation (PDO) with zero time lag. Further analyses demonstrate the connection of NPSTMW to the basin-scale ocean circulation. With this, modulations of upper-ocean structure driven by the varying strength and position of the westerlies as well as the regional air–sea heat flux pattern are seen to contribute to the variability of NPSTMW volume on interannual time scales.

Corresponding author address: Xujing Jia Davis, Physical Oceanography Dept., Woods Hole Oceanographic Institution, Clark 344b, MS#21, Woods Hole, MA 02543. E-mail: xdavis@whoi.edu

This article is included in the CLIVAR - Western Boundary Currents special collection.

Abstract

North Pacific Subtropical Mode Water (NPSTMW) is an essential feature of the North Pacific subtropical gyre imparting significant influence on regional SST evolution on seasonal and longer time scales and, as such, is an important component of basin-scale North Pacific climate variability. This study examines the seasonal-to-interannual variability of NPSTMW, the physical processes responsible for this variability, and the connections between NPSTMW and basin-scale climate signals using an eddy-permitting 1979–2006 ocean simulation made available by the Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2). The monthly mean seasonal cycle of NPSTMW in the simulation exhibits three distinct phases: (i) formation during November–March, (ii) isolation during March–June, and (iii) dissipation during June–November—each corresponding to significant changes in upper-ocean structure. An interannual signal is also evident in NPSTMW volume and other characteristic properties with volume minima occurring in 1979, 1988, and 1999. This volume variability is correlated with the Pacific decadal oscillation (PDO) with zero time lag. Further analyses demonstrate the connection of NPSTMW to the basin-scale ocean circulation. With this, modulations of upper-ocean structure driven by the varying strength and position of the westerlies as well as the regional air–sea heat flux pattern are seen to contribute to the variability of NPSTMW volume on interannual time scales.

Corresponding author address: Xujing Jia Davis, Physical Oceanography Dept., Woods Hole Oceanographic Institution, Clark 344b, MS#21, Woods Hole, MA 02543. E-mail: xdavis@whoi.edu

This article is included in the CLIVAR - Western Boundary Currents special collection.

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