Journal of Oceanography

, Volume 68, Issue 1, pp 113–126 | Cite as

Interannual variability of the North Pacific Subtropical Countercurrent: role of local ocean–atmosphere interaction

Special Section: Original Article New developments in mode-water research: Dynamic and climatic effects

Abstract

Seasonal and interannual variability of the Subtropical Countercurrent (STCC) in the western North Pacific are investigated using observations by satellites and Argo profiling floats and an atmospheric reanalysis. The STCC displays a clear seasonal cycle. It is strong in late winter to early summer with a peak in June, and weak in fall. Interannual variations of the spring STCC are associated with an enhanced subtropical front (STF) below the surface mixed layer. In climatology, the SST front induces a band of cyclonic wind stress in May north of the STCC on the background of anticyclonic curls that drive the subtropical gyre. The band of cyclonic wind and the SST front show large interannual variability and are positively correlated with each other, suggesting a positive feedback between them. The cyclonic wind anomaly is negatively correlated with the SSH and SST below. The strong (weak) cyclonic wind anomaly elevates (depresses) the thermocline and causes the fall (rise) in the SSH and SST, accelerating (decelerating) STCC to the south. It is suggested that the anomalies in the SST front and STCC in the preceding winter affect the subsequent development of the cyclonic wind anomaly in May. Results from our analysis of interannual variability support the idea that the local wind forcing in May causes the subsequent variations in STCC.

Keywords

Subtropical countercurrent Interannual variability Ocean–atmosphere interaction Sea surface temperature front 

References

  1. Aoki Y, Suga T, Hanawa K (2002) Subsurface subtropical fronts of the North Pacific as inherent boundaries in the ventilated thermocline. J Phys Oceanogr 32:2299–2311CrossRefGoogle Scholar
  2. Dinniman MS, Rienecker MM (1999) Frontogenesis in the North Pacific oceanic frontal zones: a numerical simulation. J Phys Oceanogr 29:537–559CrossRefGoogle Scholar
  3. Frankignoul C (1985) Sea surface temperature anomalies, planetary waves and air–sea feedback in the middle latitudes. Rev Geophys 23:357–390CrossRefGoogle Scholar
  4. Hosoda S, Ohira T, Nakamura T (2008) A monthly mean dataset of global oceanic temperature and salinity derived from Argo float observations. JAMSTEC Rep Res Dev 8:47–59Google Scholar
  5. Kazmin AS, Rienecker MM (1996) Variability and frontogenesis in the large-scale oceanic frontal zones. J Geophys Res 101:907–921CrossRefGoogle Scholar
  6. Kobashi F, Kawamura H (2002) Seasonal variation and instability nature of the North Pacific Subtropical Countercurrent and the Hawaiian Lee Countercurrent. J Geophys Res 107:3185. doi:10.1029/2001JC001225 Google Scholar
  7. Kobashi F, Kubokawa A (2011) Review on North Pacific Subtropical Countercurrent and Subtropical Front: role of mode water in ocean circulation and climate. J Oceanogr (this issue)Google Scholar
  8. Kobashi F, Mitsudera H, Xie S-P (2006) Three subtropical fronts in the North Pacific: observational evidence for mode water-induced subsurface frontogenesis. J Geophys Res 111:C09033. doi:10.1029/2006JC003479
  9. Kobashi F, Xie S-P, Iwasaka N, Sakamoto TT (2008) Deep atmospheric response to the North Pacific oceanic subtropical front in spring. J Climate 21:5960–5975CrossRefGoogle Scholar
  10. Kubokawa A (1999) Ventilated thermocline strongly affected by a deep mixed layer: a theory for subtropical countercurrent. J Phys Oceanogr 29:1314–1333CrossRefGoogle Scholar
  11. Kubokawa A, Inui T (1999) Subtropical countercurrent in an idealized ocean GCM. J Phys Oceanogr 29:1303–1313CrossRefGoogle Scholar
  12. Locarnini RA, Mishonov AV, Antonov JI, Boyer TP, Garcia HE (2006) World ocean atlas 2005, vol 1. In: Levitus S (ed) Temperature. NOAA atlas NESDIS 61. US Government Printing Office, Washington, DCGoogle Scholar
  13. Le Traon PY, Nadal F, Ducet N (1998) An improved mapping method of multi-satellite altimeter data. J Atmos Oceanic Technol 25:522–534Google Scholar
  14. Masuzawa J (1969) Subtropical mode water. Deep Sea Res 16:436–472Google Scholar
  15. Nakamura H (1996) A pycnostad on the bottom of the ventilated portion in the central subtropical North Pacific: its distribution and formation. J Oceanogr 52:171–188CrossRefGoogle Scholar
  16. Nakamura H, Kazmin AS (2003) Decadal changes in the North Pacific oceanic frontal zones as revealed in ship and satellite observations. J Geophys Res 108:3078. doi:10.1029/1999JC000085 Google Scholar
  17. Nonaka M, Xie S-P, Sasaki H (2011) Interannual variations in low potential vorticity water and the subtropical countercurrent in an eddy-resolving OGCM. J Oceanogr. doi:10.1007/s10872-011-0042-3 (this issue)
  18. Ohno Y, Iwasaka N, Kobashi F, Sato Y (2009) Mixed layer depth climatology of the North Pacific based on Argo observations. J Oceanogr 65:1–16CrossRefGoogle Scholar
  19. Oka E, Qiu B (2011) Progress of North Pacific mode water research in the past decade. J Oceanogr. doi:10.1007/s10872-011-0032-5 (this issue)
  20. Oka E, Talley LD, Suga T (2007) Temporal variability of winter mixed layer in the mid- to high-latitude North Pacific. J Oceanogr 63:293–307CrossRefGoogle Scholar
  21. Onogi K, Tsutsui J, Koide H, Sakamoto M, Kobayashi S, Hatsushika H, Matsumoto T, Yamazaki N, Kamahori H, Takahashi K, Kadokura S, Wada K, Kato K, Oyama R, Ose T, Mannoji N, Taira R (2007) The JRA-25 reanalysis. J Meteor Soc Japan 85:369–432CrossRefGoogle Scholar
  22. Qiu B (1999) Seasonal eddy field modulation of the North Pacific subtropical countercurrent: TOPEX/Poseidon observations and theory. J Phys Oceanogr 29:2471–2486CrossRefGoogle Scholar
  23. Qiu B, Chen S (2006) Decadal variability in the formation of the North Pacific subtropical mode water: oceanic versus atmospheric control. J Phys Oceanogr 36:1365–1380CrossRefGoogle Scholar
  24. Qiu B, Chen S (2010) Interannual variability of the North Pacific Subtropical Countercurrent and its associated mesoscale eddy field. J Phys Oceanogr 40:213–225CrossRefGoogle Scholar
  25. Reynolds RW, Smith TM, Liu C, Chelton DB, Casey KS, Schlax MG (2007) Daily high-resolution blended analyses for sea surface temperature. J Climate 20:5473–5496CrossRefGoogle Scholar
  26. Sasaki H, Xie S-P, Taguchi B, Nonaka M, Hosoda S, Masumoto Y (2011) Interannual variations of the Hawaiian Lee Countercurrent induced by low potential vorticity water ventilation in the subsurface. J Oceanogr (this issue)Google Scholar
  27. Suga T, Takei Y, Hanawa K (1997) Thermostad distribution in the North Pacific subtropical gyre: the central mode water and the subtropical mode water. J Phys Oceanogr 27:140–152CrossRefGoogle Scholar
  28. Sugimoto S, Hanawa K (2010) Impact of Aleutian low activity on the STMW formation in the Kuroshio recirculation gyre region. Geophys Res Lett 37:L03606. doi:10.1029/2009GL041795
  29. Takeuchi K (1984) Numerical study of the Subtropical Front and the Subtropical Countercurrent. J Oceanogr Soc Japan 40:371–381CrossRefGoogle Scholar
  30. Takeuchi E, Yasuda I (2003) Wintertime shoaling of oceanic surface mixed layer. Geophys Res Lett 30(22):2152. doi:10.1029/2003GL018511 Google Scholar
  31. Tokinaga H, Xie S-P, Kobashi F, Tanimoto Y (2009) Local and remote influences of the Kuroshio Extension on the atmosphere. US CLIVAR Variations 7:1–4Google Scholar
  32. Uda M, Hasunuma K (1969) The eastward subtropical countercurrent in the western North Pacific Ocean. J Oceanogr Soc Japan 25:201–210Google Scholar
  33. White WB, Hasunuma K, Solomon H (1978) Large-scale seasonal, secular variability of the subtropical front in the western North Pacific from 1954 to 1974. J Geophys Res 83:4531–4544CrossRefGoogle Scholar
  34. Xie S-P, Deser C, Vecchi GA, Ma J, Teng H, Wittenberg AT (2010) Global warming pattern formation: sea surface temperature and rainfall. J Climate 23:966–986CrossRefGoogle Scholar
  35. Xie S-P, Xu L-X, Liu Q, Kobashi F (2011) Dynamical role of mode-water ventilation in decadal variability in the central subtropical gyre of the North Pacific. J Climate 24:1212–1225CrossRefGoogle Scholar
  36. Xu L-X, Xie S-P, Liu Q, Kobashi F (2011) Response of the North Pacific subtropical countercurrent and its variability to global warming. J Oceanogr. doi:10.1007/s10872-011-0031-6 (this issue)
  37. Yamanaka G, Ishizaki H, Hirabara M, Ishikawa I (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
  38. Yasuda T, Hanawa K (1997) Decadal changes in the mode waters in the midlatitude North Pacific. J Phys Oceanogr 27:858–870CrossRefGoogle Scholar
  39. Yoshida K, Kidokoro T (1967a) A subtropical countercurrent in the North Pacific: an eastward flow near the Subtropical Convergence. J Oceanogr Soc Japan 23:88–91Google Scholar
  40. Yoshida K, Kidokoro T (1967b) A subtropical countercurrent (II): a prediction of eastward flows at lower subtropical latitudes. J Oceanogr Soc Japan 23:231–236Google Scholar

Copyright information

© The Oceanographic Society of Japan and Springer 2011

Authors and Affiliations

  1. 1.Faculty of Marine TechnologyTokyo University of Marine Science and TechnologyTokyoJapan
  2. 2.Research Institute for Global ChangeJapan Agency for Marine-Earth Science and TechnologyYokosukaJapan
  3. 3.International Pacific Research Center (IPRC) and Department of Meteorology, School of Ocean and Earth Science and Technology (SOEST), University of Hawaii at ManoaHonoluluUSA

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