• Akima, H., 1970: A new method of interpolation and smooth curve fitting based on local procedures. J. Assoc. Comput. Mach., 17 , 589603.

    • Search Google Scholar
    • Export Citation
  • Bingham, F. M., 1992: Formation and spreading of Subtropical Mode Water in the North Pacific. J. Geophys. Res., 97 , 1117711189.

  • Boyer, T. P., , C. Stephens, , J. I. Antonov, , M. E. Conkright, , R. A. Locarnini, , T. D. O’Brien, , and H. E. Garcia, 2002: Salinity. Vol. 2, World Ocean Atlas 2001, NOAA Atlas NESDIS 50, CD-ROM.

  • Gilson, J., , and D. Roemmich, 2002: Mean and temporal variability in Kuroshio geostrophic transport south of Taiwan (1993–2001). J. Oceanogr., 58 , 183195.

    • Search Google Scholar
    • Export Citation
  • Gordon, A. L., , J. R. E. Lutjeharms, , and M. L. Grundlingh, 1987: Stratification and circulation at the Agulhas retroflection. Deep-Sea Res., 34 , 565599.

    • Search Google Scholar
    • Export Citation
  • Hanawa, K., 1987: Interannual variations in the wintertime outcrop area of Subtropical Mode Water in the North Pacific. Atmos.–Ocean, 25 , 358374.

    • Search Google Scholar
    • Export Citation
  • Hanawa, K., , and I. Hoshino, 1988: Temperature structure and mixed layer in the Kuroshio region over the Izu Ridge. J. Mar. Res., 46 , 683700.

    • 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
  • Hanawa, K., , and L. D. Talley, 2001: Mode Waters. Ocean Circulation and Climate: Observing and Modelling the Global Ocean, G. Siedler et al., Eds., Academic Press, 373–386.

    • Search Google Scholar
    • Export Citation
  • Maharaj, A. M., , P. Cipolini, , and N. J. Holbrook, 2005: Observed variability of the South Pacific westward sea level anomaly signal in the presence of bottom topography. Geophys. Res. Lett., 32 .L04611, doi:10.1029/2004GL020966.

    • Search Google Scholar
    • Export Citation
  • Masuzawa, J., 1969: Subtropical Mode Water. Deep-Sea Res., 16 , 453472.

  • Mulhearn, P. J., 1987: The Tasman Front: A study using satellite infrared imagery. J. Phys. Oceanogr., 17 , 11481155.

  • Nakamura, H., 1996: A pycnostad on the bottom of the ventilated portion in the central subtropical North Pacific: Its distribution and formation. J. Oceanogr., 52 , 172188.

    • Search Google Scholar
    • Export Citation
  • 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
  • Oka, E., , and T. Suga, 2005: Differential formation and circulation of North Pacific Central Mode Water. J. Phys. Oceanogr., 35 , 19972011.

    • Search Google Scholar
    • Export Citation
  • Provost, C., , C. Escoffier, , K. Maamaatuaiahutapu, , A. Kartavtseff, , and V. Garcon, 1999: Subtropical Mode Waters in the South Atlantic Ocean. J. Geophys. Res., 104 , 2103321049.

    • Search Google Scholar
    • Export Citation
  • Reynolds, R. W., , N. A. Rayner, , T. M. Smith, , D. C. Stokes, , and W. Wang, 2002: An improved in situ and satellite SST analysis for climate. J. Climate, 15 , 16091625.

    • Search Google Scholar
    • Export Citation
  • Ridgway, K. R., , and J. R. Dunn, 2003: Mesoscale structure of the mean East Australian Current System and its relationship with topography. Prog. Oceanogr., 56 , 189222.

    • Search Google Scholar
    • Export Citation
  • Roemmich, D., , and B. Cornuelle, 1990: Observing the fluctuations of gyre-scale ocean circulation: A study of the subtropical South Pacific. J. Phys. Oceanogr., 20 , 19191934.

    • Search Google Scholar
    • Export Citation
  • Roemmich, D., , and B. Cornuelle, 1992: The Subtropical Mode Waters of the South Pacific Ocean. J. Phys. Oceanogr., 22 , 11781187.

  • 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
  • Simmons, A., , and J. Gibson, 2000: The ERA-40 project plan. ERA-40 Project Rep. Series 1, ECMWF, 63 pp.

  • Sprintall, J., , D. Roemmich, , B. Stanton, , and R. Bailey, 1995: Regional climate variability and ocean heat transport in the southwest Pacific Ocean. J. Geophys. Res., 100 , 1586515871.

    • Search Google Scholar
    • Export Citation
  • Stanton, B. R., 1979: The Tasman Front. N. Z. J. Mar. Freshwater Res., 13 , 201214.

  • Stephens, C., , J. I. Antonov, , T. P. Boyer, , M. E. Conkright, , R. A. Locarnini, , T. D. O’Brien, , and H. E. Garcia, 2002: Temperature. Vol. 1, World Ocean Atlas 2001, NOAA Atlas NESDIS 49, CD-ROM.

  • 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 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.

  • Suga, T., , Y. Takei, , and K. Hanawa, 1997: Thermostad distribution in the North Pacific subtropical gyre: The Central Mode Water and the Subtropical Mode Water. J. Phys. Oceanogr., 27 , 140152.

    • 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 , 1959119598.

    • Search Google Scholar
    • Export Citation
  • Tilburg, C. E., , H. E. Hurlburt, , J. J. O’Brien, , and J. F. Shriver, 2001: The dynamics of the East Australian Current system: The Tasman Front, the East Auckland Current, and the East Cape Current. J. Phys. Oceanogr., 31 , 29172943.

    • Search Google Scholar
    • Export Citation
  • Wakata, Y., , T. Setou, , I. Kaneko, , H. Uchida, , and S. Imawaki, 2006: Interannual variability of the Kuroshio transport passing through the 137°E meridian in an OGCM related to the North Pacific windstress. J. Oceanogr., 62 , 2535.

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

  • Yasuda, T., , and Y. Kitamura, 2003: Long-term variability of North Pacific Subtropical Mode Water in response to spin-up of subtropical gyre. J. Oceanogr., 59 , 279290.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 139 139 11
PDF Downloads 83 83 12

Three Types of South Pacific Subtropical Mode Waters: Their Relation to the Large-Scale Circulation of the South Pacific Subtropical Gyre and Their Temporal Variability

View More View Less
  • 1 Department of Geophysics, Tohoku University, Sendai, Japan
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

A detailed spatial distribution of South Pacific Subtropical Mode Water (SPSTMW) and its temporal variation were investigated using the World Ocean Atlas (WOA) 2001 climatology and high-resolution expendable bathythermograph (HRX) line data. In the WOA 2001 climatology, SPSTMW can be classified into western and eastern parts. A detailed examination of spatial distributions using HRX-PX06 line data revealed that the eastern part can be further divided into two types by the Tasman Front (TF) extension. Consequently, SPSTMW can be classified into three types, referred to in the present study as the West, North, and South types. The West type, situated in the recirculation region of the East Australia Current (EAC), has a core layer temperature (CLT) of about 19.1°C; the North type, in the region north of the TF extension, has a CLT of about 17.6°C; and the South type, in the region south of the TF extension, has a CLT of about 16.0°C. The long-term (>6 yr) variations in the inventories of the three types were dissimilar to each other. The short-term (<6 yr) and long-term variations in the mean CLT of the North and South types were greater than that of the West type. Winter cooling in the previous year may have influenced the short-term variation in the South-type CLT. Moreover, the strength of the EAC may have influenced long-term variation in the West-type inventory and thickness and in the North-type thickness and CLT.

Corresponding author address: Takamasa Tsubouchi, Department of Geophysics, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan. Email: t-taka@pol.geophys.tohoku.ac.jp

Abstract

A detailed spatial distribution of South Pacific Subtropical Mode Water (SPSTMW) and its temporal variation were investigated using the World Ocean Atlas (WOA) 2001 climatology and high-resolution expendable bathythermograph (HRX) line data. In the WOA 2001 climatology, SPSTMW can be classified into western and eastern parts. A detailed examination of spatial distributions using HRX-PX06 line data revealed that the eastern part can be further divided into two types by the Tasman Front (TF) extension. Consequently, SPSTMW can be classified into three types, referred to in the present study as the West, North, and South types. The West type, situated in the recirculation region of the East Australia Current (EAC), has a core layer temperature (CLT) of about 19.1°C; the North type, in the region north of the TF extension, has a CLT of about 17.6°C; and the South type, in the region south of the TF extension, has a CLT of about 16.0°C. The long-term (>6 yr) variations in the inventories of the three types were dissimilar to each other. The short-term (<6 yr) and long-term variations in the mean CLT of the North and South types were greater than that of the West type. Winter cooling in the previous year may have influenced the short-term variation in the South-type CLT. Moreover, the strength of the EAC may have influenced long-term variation in the West-type inventory and thickness and in the North-type thickness and CLT.

Corresponding author address: Takamasa Tsubouchi, Department of Geophysics, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan. Email: t-taka@pol.geophys.tohoku.ac.jp

Save