Abstract
With high-resolution conductivity-temperature-depth (CTD) observations conducted in Oct.–Nov. 2005, this study provides a detailed quasi-synoptic description of the North Pacific Tropic Water (NPTW), North Pacific Intermediate Water (NPIW) and Antarctic Intermediate Water (AAIW) in the western North Pacific. Some novel features are found. NPTW enters the western ocean with highest-salinity core off shore at 15°–18°N, and then splits to flow northward and southward along the western boundary. Its salinity decreases and density increases outside the core region. NPIW spreads westward north of 15°N with lowest salinity off shore at 21°N, but mainly hugs the Mindanao coast south of 12°N. It shoals and thins toward the south, with salinity increasing and density decreasing. AAIW extends to higher latitude off shore than that in shore, and it is traced as a salinity minimum to only 10°N at 130°E. Most of the South Pacific waters turn northeastward rather than directly flow northward upon reaching to the Mindanao coast, indicating the eastward shift of the Mindanao Undercurrent (MUC).
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References
Bingham F M, Lukas R. 1994. The southward intrusion of North Pacific Intermediate Water along the Mindanao coast. J. Phys. Oceanogr., 24: 141–154.
Bingham F M, Lukas R. 1995. The distribution of intermediate water in the western equatorial Pacific during January-February 1986. Deep-Sea Res., I 42: 1 545–1 573.
Cannon G A. 1970. Characteristics of Waters East of Mindanao, Philippine Islands, August, 1965. In: Marr J C ed., The Kuroshio, A Symposium on the Japan Current, East-West Center, Honolulu, Hawaii. p. 205–211.
Chen C-T A, Wang S L, Wang B J et al. 2001. Nutrient budgets for the South China Sea basin, Mar. Chem., 75: 281–300.
Fine R A, Lukas R, Bingham F M, Warner M J et al. 1994. The western equatorial Pacific: A water mass crossroad. J. Geophs. Res., 99(12): 25 063–25 080.
Firing E, Kashina Y, Hacker P. 2005. Energetic subthermocline currents observed east of Mindanao. Deep-Sea Res. II, 52: 605–613.
Hu D, Cui M. 1989. The Western Boundary Current in the Far-Western Pacific Ocean, Progress of Western International Meeting and Workshop on TOGA CORAE, May 24–30, Noumea, New Caledonia, edited by J. Picaut, R. Lukas and T. Delcroix, p. 123–134.
Hu D, Cui M. 1991. The western boundary current of the Pacific and its role in the climate, J. Oceanol. Limnol., 9(1): 1–14.
Kaneko I, Takatsuki Y, Kamiya H. 2001. Circulation of intermediate and deep waters in the Philippine Sea. J. Oceanogr., 57: 397–420.
Kashino Y, Watanabe H, Herunadi B et al. 1999. Current variability at the Pacific entrance of the Indonesian Throughflow. J. Geophys. Res., 104: 11 021–11 035.
Lindstrom E R, Lukas R, Fine R et al. (1987). The western equatorial Pacific Ocean circulation study, Nature, 330: 533–537.
Nitani H. 1972. Beginning of the Kuroshio, In: Kuroshio: Physical Aspects of Japan Current, Stommel H, Yoshida eds, University of Washington Press, EDS. p.129–163.
McCreary J P, Lu P. 1994. On the interaction between the subtropical and the equatorial oceans: The subtropical cell. J. Phys. Oceanogr., 24: 466–497.
Qu T, Lindstrom E J. 2002. A climatological interpretation of the circulation in the western South Pacific. J. Phys. Oceanogr., 32: 2 492–2 508.
Qu T, Lindstrom E J. 2004. Northward intrusion of the Antarctic Intermediate Water in the western Pacific. J. Phys. Oceanogr., 34: 2 104–2 118.
Qu T, Kagimoto T, Yamagata, T. 1997. A subsurface countercurrent along the east coast of Luzon. Deep-sea Res. I., 44: 431–423.
Qu T, Mistudera H, Yamagata T. 1998. On the western boundary currents in the Philippine Sea. J. Geophs. Res., 103(4): 7 537–7 548.
Qu T, Mitsudera H, Yamagata T. 1999. A climatology of the circulation and water mass distribution near the Philippine coast. J. Phys. Oceanogr., 29: 1 488–1 505.
Reid J L. 1965. Intermediate waters of the Pacific Ocean. Johns Hopkins Oceanogr. Studi., 2: 85.
Rochford D J. 1960. The intermediate depth waters of the Tasman and Coral Sea. I. The 27.20σt surface. Aust. J. Mar. Freshwater Res., 11: 127–147.
Talley L D. 1993. Distribution and formation of North Pacific Intermediate Water. J. Phys. Oceanog., 23: 517–537.
Tian J, Yang Q, Liang X et al. 2006. The Observation of Luzon Strait Transport. Geophys. Res. Lett., 33: L19607.
Tozuka T, Kagimoto T, Masumoto Y et al. 2002. Simulated Multiscale Variations in the Western Tropical Pacific: The Mindanao Dome Revisited. J. Phys. Oceanogr, 32: 1 338–1 359.
Tsuchiya M, Lukas R, Fine A et al. 1989. Source waters of the Pacific equatorial undercurrent. Progress in Oceanogr., 23: 101–147.
Tsuchiya M. 1991. Flow path of Antarctic Intermediate Waters in the western equatorial Pacific Ocean. J. Mar. Res., 38A(suppl.): 272–279.
Tsuchiya M. 1968. Upper waters of the intertropical Pacific Ocean. Johns Hopkins Oceanogr. Stud., l4: 50.
Wang F, Hu D. 1998. Dynamic and thermohaline properties of the Mindanao Undercurrent II thermohaline structure. Chin. J. Oceanol. Limnol., 16(3): 206–213.
Wyrtki K. 1961. Physical Oceanography of the Southeast Asian Waters, NAGA Report 2, Ins. of Oceanogr., University of California, San Diego, La Joola, CA. p.195
Zang N. 2008. The distribution of Several Western Boundary Undercurrents and the corresponding dynamic Mechanism. Ph D Dissertation. (in Chinese with English abstract)
Zhang Y H. 2006. The analysis of the subsurface water masses and intermediate water masses of the Tropical Western Pacific and their decadal variation. PhD Dissertation. (in Chinese with English abstract)
Zhou H. 2006. A study of some characteristics and variability of the North Pacific western boundary current system. PhD Dissertation. (in Chinese with English abstract)
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Supported by the National Natural Science Foundation of China (Nos. 40890153 and 40576016)
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Xie, L., Tian, J., Hu, D. et al. A quasi-synoptic interpretation of water mass distribution and circulation in the western North Pacific: I. Water mass distribution. Chin. J. Ocean. Limnol. 27, 630–639 (2009). https://doi.org/10.1007/s00343-009-9161-8
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DOI: https://doi.org/10.1007/s00343-009-9161-8