Assessment of the Effects of Tidal Mixing in the Kuril Straits on the Formation of the North Pacific Intermediate Water

Yuki Tanaka Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Tokyo, Japan

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Toshiyuki Hibiya Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Tokyo, Japan

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Yoshihiro Niwa Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Tokyo, Japan

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Abstract

To assess accurately the effect of tidal mixing in the Kuril Straits on the formation of the North Pacific Intermediate Water (NPIW), the spatial distribution of diapycnal diffusivity recently obtained by the present authors is incorporated into an eddy-permitting OGCM. It is shown that the NPIW is successfully reproduced, although the diapycnal diffusivity averaged over the entire Kuril Straits is an order of magnitude less than has previously been assumed as a tuning parameter to reproduce the NPIW in low-resolution OGCMs. This strongly suggests that the effect of tidal mixing in the Kuril Straits on the formation of the NPIW is relatively minor and that the physical processes omitted by the low-resolution OGCMs, such as isopycnal mixing along the Kuroshio Extension region, are much more important. This suggestion gives warning of the danger that some misleading conclusions might be derived from OGCMs that employ diapycnal diffusivity just as a tuning parameter to reproduce the observed features.

* Current affiliation: Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan

Corresponding author address: Toshiyuki Hibiya, Dept. of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan. Email: hibiya@eps.s.u-tokyo.ac.jp

Abstract

To assess accurately the effect of tidal mixing in the Kuril Straits on the formation of the North Pacific Intermediate Water (NPIW), the spatial distribution of diapycnal diffusivity recently obtained by the present authors is incorporated into an eddy-permitting OGCM. It is shown that the NPIW is successfully reproduced, although the diapycnal diffusivity averaged over the entire Kuril Straits is an order of magnitude less than has previously been assumed as a tuning parameter to reproduce the NPIW in low-resolution OGCMs. This strongly suggests that the effect of tidal mixing in the Kuril Straits on the formation of the NPIW is relatively minor and that the physical processes omitted by the low-resolution OGCMs, such as isopycnal mixing along the Kuroshio Extension region, are much more important. This suggestion gives warning of the danger that some misleading conclusions might be derived from OGCMs that employ diapycnal diffusivity just as a tuning parameter to reproduce the observed features.

* Current affiliation: Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan

Corresponding author address: Toshiyuki Hibiya, Dept. of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan. Email: hibiya@eps.s.u-tokyo.ac.jp

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  • Conkright, M. E., R. A. Locarnini, H. E. Garcia, T. D. O’Brien, T. P. Boyer, C. Stephens, and J. I. Antonov, 2002: World Ocean Atlas 2001: Objective Analyses, Data Statistics, and Figures CD-ROM Documentation. National Oceanographic Data Center Internal Rep. 17, 21 pp. [Available online at ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/readme.pdf].

    • Search Google Scholar
    • Export Citation
  • Hasumi, H., I. Yasuda, H. Tatebe, and M. Kimoto, 2008: Pacific bidecadal climate variability regulated by tidal mixing around the Kuril Islands. Geophys. Res. Lett., 35 , L14601. doi:10.1029/2008GL034406.

    • Search Google Scholar
    • Export Citation
  • Ishikawa, I., and H. Ishizaki, 2009: Importance of eddy representation for modeling the intermediate salinity minimum in the North Pacific: Comparison between eddy-resolving and eddy-permitting models. J. Oceanogr., 65 , 407426.

    • Search Google Scholar
    • Export Citation
  • Ishizaki, H., and I. Ishikawa, 2004: Simulation of formation and spreading of salinity minimum associated with NPIW using a high-resolution model. J. Oceanogr., 60 , 463485.

    • Search Google Scholar
    • Export Citation
  • Itoh, M., K. I. Ohshima, and M. Wakatsuchi, 2003: Distribution and formation of Okhotsk Sea Intermediate Water: An analysis of isopycnal climatological data. J. Geophys. Res., 108 , 3258. doi:10.1029/2002JC001590.

    • Search Google Scholar
    • Export Citation
  • Itoh, S., I. Yasuda, T. Nakatsuka, J. Nishioka, and Y. N. Volkov, 2010: Fine- and microstructure observations in the Urup Strait, Kuril Islands, during August of 2006. J. Geophys. Res., 115 , C08004. doi:10.1029/2009JC005629.

    • Search Google Scholar
    • Export Citation
  • Katsumata, K., K. I. Ohshima, T. Kono, M. Itoh, I. Yasuda, Y. N. Volkov, and M. Wakatsuchi, 2004: Water exchange and tidal currents through the Bussol’ Strait revealed by direct current measurements. J. Geophys. Res., 109 , C09S06. doi:10.1029/2003JC001864.

    • Search Google Scholar
    • Export Citation
  • Kawasaki, T., and H. Hasumi, 2010: Role of localized mixing around the Kuril Straits in the Pacific thermohaline circulation. J. Geophys. Res., 115 , C11002. doi:10.1029/2010JC006130.

    • Search Google Scholar
    • Export Citation
  • Kowalik, Z., and I. Polyakov, 1998: Tides in the Sea of Okhotsk. J. Phys. Oceanogr., 28 , 13891409.

  • Large, W. C., J. C. McWilliams, and S. C. Doney, 1994: Oceanic vertical mixing: A review and a model with a nonlocal boundary layer parametrization. Rev. Geophys., 32 , 363403.

    • 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 , 57535766.

    • Search Google Scholar
    • Export Citation
  • Matsuda, J., H. Mitsudera, T. Nakamura, K. Uchimoto, T. Nakanowatari, and N. Ebuchi, 2009: Wind and buoyancy driven intermediate-layer overturning in the Sea of Okhotsk. Deep-Sea Res. I, 56 , 14011418.

    • Search Google Scholar
    • Export Citation
  • Nakamura, T., and T. Awaji, 2004: Tidally induced diapycnal mixing in the Kuril Straits and its role in water transformation and transport: A three-dimensional nonhydrostatic model experiment. J. Geophys. Res., 109 , C09S07. doi:10.1029/2003JC001850.

    • Search Google Scholar
    • Export Citation
  • Nakamura, T., T. Toyoda, Y. Ichikawa, and T. Awaji, 2006a: Effects of tidal mixing at the Kuril Straits on North Pacific ventilation: Adjustment of the intermediate layer revealed from numerical experiments. J. Geophys. Res., 111 , C04003. doi:10.1029/2005JC003142.

    • Search Google Scholar
    • Export Citation
  • Nakamura, T., T. Toyoda, Y. Ichikawa, and T. Awaji, 2006b: Enhanced ventilation in the Okhotsk Sea through tidal mixing at the Kuril Straits. Deep-Sea Res. I, 53 , 425448.

    • Search Google Scholar
    • Export Citation
  • Ohshima, K. I., M. Wakatsuchi, Y. Fukamachi, and G. Mizuta, 2002: Near-surface circulation and tidal currents of the Okhotsk Sea observed with satellite-tracked drifters. J. Geophys. Res., 107 , 3195. doi:10.1029/2001JC001005.

    • Search Google Scholar
    • Export Citation
  • Ono, K., K. I. Ohshima, T. Kono, M. Itoh, K. Katsumata, Y. N. Volkov, and M. Wakatsuchi, 2007: Water mass exchange and diapycnal mixing at Bussol’ Strait revealed by water mass properties. J. Oceanogr., 63 , 281291.

    • Search Google Scholar
    • Export Citation
  • Rabinovich, A. B., and R. E. Thomson, 2001: Evidence of diurnal shelf waves in satellite-tracked drifter trajectories off the Kuril Islands. J. Phys. Oceanogr., 31 , 26502668.

    • Search Google Scholar
    • Export Citation
  • Reid, J. L., 1965: Intermediate Waters of the Pacific Ocean. The Johns Hopkins Oceanographic Studies Series, No. 2, The Johns Hopkins Press, 85 pp.

    • Search Google Scholar
    • Export Citation
  • Sasajima, Y., H. Hasumi, and T. Nakamura, 2010: A sensitivity study on the dense shelf water formation in the Okhotsk Sea. J. Geophys. Res., 115 , C11007. doi:10.1029/2009JC005697.

    • Search Google Scholar
    • Export Citation
  • St. Laurent, L. C., H. L. Simmons, and S. R. Jayne, 2002: Estimating tidally driven mixing in the deep ocean. Geophys. Res. Lett., 29 , 2106. doi:1029/2002GL015633.

    • Search Google Scholar
    • Export Citation
  • Sverdrup, H. M., W. Johnson, and R. H. Fleming, 1942: The Oceans: Their Physics, Chemistry, and General Biology. Prentice Hall, 1087 pp.

    • Search Google Scholar
    • Export Citation
  • Talley, L. D., 1991: An Okhotsk Sea anomaly: Implication for ventilation in the North Pacific. Deep-Sea Res., 38 , S171S190.

  • Talley, L. D., 1993: Distribution and formation of North Pacific Intermediate Water. J. Phys. Oceanogr., 23 , 517537.

  • Talley, L. D., 1997: North Pacific Intermediate Water transports in the mixed water region. J. Phys. Oceanogr., 27 , 17951803.

  • Talley, L. D., Y. Nagata, M. Fujimura, T. Iwao, T. Kono, D. Inagake, M. Hirai, and K. Okuda, 1995: North Pacific Intermediate Water in the Kuroshio/Oyashio mixed water region. J. Phys. Oceanogr., 25 , 475501.

    • Search Google Scholar
    • Export Citation
  • Tanaka, Y., T. Hibiya, and Y. Niwa, 2007: Estimates of tidal energy dissipation and diapycnal diffusivity in the Kuril Straits using TOPEX/POSEIDON altimeter data. J. Geophys. Res., 112 , C10021. doi:10.1029/2007JC004172.

    • Search Google Scholar
    • Export Citation
  • Tanaka, Y., T. Hibiya, Y. Niwa, and N. Iwamae, 2010: Numerical study of K1 internal tides in the Kuril straits. J. Geophys. Res., 115 , C09016. doi:10.1029/2009JC005903.

    • Search Google Scholar
    • Export Citation
  • Tatebe, H., and I. Yasuda, 2004: Oyashio southward intrusion and cross-gyre transport related to diapycnal upwelling in the Okhotsk Sea. J. Phys. Oceanogr., 34 , 23272341.

    • Search Google Scholar
    • Export Citation
  • Yasuda, I., 1997: The origin of the North Pacific Intermediate Water. J. Geophys. Res., 102 , 893909.

  • Yasuda, I., 2004: North Pacific Intermediate Water: Progress in SAGE (SubArctic Gyre Experiment) and related projects. J. Oceanogr., 60 , 385395.

    • Search Google Scholar
    • Export Citation
  • Yasuda, I., K. Okuda, and Y. Shimizu, 1996: Distribution and modification of North Pacific Intermediate Water in the Kuroshio–Oyashio interfrontal zone. J. Phys. Oceanogr., 26 , 448465.

    • Search Google Scholar
    • Export Citation
  • Yasuda, I., S. Kouketsu, K. Katsumata, M. Ohiwa, Y. Kawasaki, and A. Kusaka, 2002: Influence of Okhotsk Sea Intermediate Water on the Oyashio and North Pacific Intermediate Water. J. Geophys. Res., 107 , 3237. doi:10.1029/2001JC001037.

    • Search Google Scholar
    • Export Citation
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