Abstract
On the basis of the conductivity temperature depth (CTD) observation data off the coast of the Philippines (7.5˚–18˚N, 130˚E–the east coast of the Philippines) in the fall of 2005, the water mass distribution, geostrophic flow field, and heat budget are examined. Four water masses are present: the North Pacific Tropical Surface Water, the North Pacific Sub-surface Water, the North Pacific Intermediate Water, and the Antarctic Intermediate Water (AAIW). The previous three corresponded with the North Equatorial Current (NEC), the Kuroshio Current (KC), and the Mindanao Current (MC), respectively. AAIW is the source of the Mindanao Undercurrent. The mass transport of NEC, KC, and MC is 58.7, 15, and 27.95 Sv, respectively (relative to 1500 db). NEC can be balanced by the transport across the whole transect 18˚N (31.81 Sv) and 7.5˚N (26.11 Sv) but not simply by KC and MC. Direct calculation is used to study the heat flux. In sum, 1.45 PW heat is transported outwards the observed region, which is much more than that released from the ocean to the air at the surface (0.05 PW). The net heat lost decreased the water temperature by 0.75℃ each month on average, and the trend agreed well with the SST change. Vertically, the heat transported by the currents is mainly completed in the upper 500 m.
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References
Bryden, H. L., and Hall, M. M., 1980. Heat transport by currents across 25°N latitude in the Atlantic Ocean. Science, 207 (4433): 884–886.
Bryden, H. L., Roemmich, D. H., and Church, J. A., 1991. Ocean heat transport across 24°N in the Pacific. Deep-Sea Research, 38: 297–324.
Carissimo, B. C., Oort, A. H., and Vonder, H. T. H., 1985. Estimates of the meridional energy transports in the atmosphere and ocean. Journal of Physical Oceanography, 15: 82–91.
Chao, J. P., Chen, Z. S., and Wang, Z. S., 1993. A Comprehensive Study of Air-Sea Interaction in the Tropical Western Pacific. Ocean Press, Beijing, 256pp (in Chinese).
Ding, L. M., 2000. Analysis of air-sea heat exchange in the subtropical waters of the Northwest Pacific Ocean. Chinese Anthology of Oceanography, 11: 122–127 (in Chinese with English abstract).
Hall, M. M., and Bryden, H. L., 1982. Direct estimates and mechanisms of ocean heat transport. Deep Sea Research, Part A, 29 (3): 339–359.
Hsiung, J., 1985. Estimates of global oceanic meridional heat transport. Journal of Physical Oceanography, 15: 1405–1413.
Hsiung, J., Newell, R. E., and Houghtby, T., 1989. The annual cycle of oceanic heat storage and oceanic meridional heat transport. Quarterly Journal of the Royal Meteorological Society, 115: 1–28.
Hu, D., and Cui, M., 1989. The western boundary current in the far-western Pacific Ocean. Proceedings of the Western Pacific International Meeting and Workshop on TOGA-COARE. ORSTOM, Noumea, New Caledonia, 24–30.
Hu, R. J., 2003. Study on the heat budget and meridional circulation in the tropical Indian Ocean. PhD thesis. Ocean University of China, Qingdao (in Chinese).
Hu, R. J., Liu, Q. Y., and Meng, X. F., 2005. The seasonal and interannual variabilities in the meridional heat transport and heat budget in the northern Indian Ocean. Periodical of Ocean University of China, 35 (3): 363–369 (in Chinese with English abstract).
Jiang, Q. R., and Zheng, D. Y., 1997. Seasonal variation of sea surface heat flux budget in North Pacific and its relation to SST. Scientia Meteorologica Sinica, 17 (2): 143–150 (in Chinese with English abstract).
Li, X. L., 1993a. Water mass features in the upper part of section along 130°E in western tropical Pacific Ocean and their responses to El Niño and anti-El Niño. Marine Science Bulletin, 12 (5): 9–14 (in Chinese with English abstract).
Li, X. L., 1993b. Water mass features in the upper part of section along 18°20′N in western tropical Pacific Ocean and their responses to El Niño and anti-El Niño. Acta Oceanologica Sinica, 15 (4): 12–18 (in Chinese with English abstract).
Li, X. L., 1993c. OatWater mass features in the upper part of section along 8°N in western tropical Pacific Ocean and their responses to El Niño and anti-El Niño. Journal of Oceanography in Taiwan Strait, 12 (1): 41–47 (in Chinese with English abstract).
Liu, Y. Y., Liu, Q. Y., and Pan, A. J., 2004. Seasonal, annual and decadal variations of air-sea heat fluxes in the northern Pacific Ocean. Periodical of Ocean University of China, 34 (3): 341–350 (in Chinese with English abstract).
Lukas, R., Firing, E., Hacker, P., Richardson, P. L., Collins, C. A., Fine, R., and Gammon, R., 1991. Observations of the Mindanao Current during the western equatorial Pacific Ocean circulation study. Journal of Geophysical Research, 96: 7098–7104.
Macdonald, A. M., 1993. Property fluxes at 30°S and their implications for the Pacific-Indian Throughflow and the global heat budget. Journal of Geophysical Research, 98 (C4): 6851–6868.
Nitani, H., 1972. Beginning of the Kuroshio. In: Kuroshio: Physical Aspects of the Japan Current.
Stommel, H., and Yoshida, K., eds., University of Washington Press, Seattle, 129–163.
Qu, T. D., and Mitsudera, H., 1999. A climatology of the circulation and water mass distribution near the Philippine coast. Journal of Physical Oceanography, 29 (7): 1488–1505.
Qu, T. D., Mitsudera, H., and Yamagata, T., 1998. On the western boundary currents in the Philippine Sea. Journal of Geophysical Research, 103: 7537–7548.
Reid, J. L., 1973. The shallow salinity minima of the Pacific Ocean. Deep Sea Research, 20: 51–68.
Sun, C. H., Liu, Z. H., Tong, M. R., Zhu, B. K., and Xu, J. P., 2007. The application of Argo data to water masses analysis in the Northwest Pacific Ocean. Journal of Marine Science, 25 (3): 1–13 (in Chinese with English abstract).
Sun, X. P., 2000. A comparison of characteristics between the subtropical countercurrent, the North Equatorial Current and the North Equatorial Countercurrent in the northwestern Pacific Ocean. Journal of Oceanography of Huanghai & Bohai Seas, 18 (1): 1–12 (in Chinese with English abstract).
Toole, J. M., Millard, R. C., Wang, Z., and Pu, S., 1990. Observations of the Pacific North Equatorial Current bifurcation at the Philippine coast. Journal of Physical Oceanography, 20: 307–318.
Trenberth, K. E., and Solomon, A., 1994. The global heat balance: Heat transports in the atmosphere and ocean. Climate Dynamics, 10: 107–134.
Wang, F., Zhang, P., Hu, D. X., and Seidel, H., 2001. Tropical Western Pacific Circulation and its seasonal variation. Chinese Science Bulletin, 46 (23): 1997–2002 (in Chinese).
Wang, J., and Chern, C. S., 1997. On the trajectory of subsurface and intermediate waters in the northeastern South China Sea. Tropic Oceanology, 16 (2): 24–41 (in Chinese with English abstract).
Wen, N., and Liu, Q. Y., 2006. Winter ocean-atmosphere interaction in the Northwest Pacific. Oceanologia et Limnologia Sinica, 37 (3): 264–270 (in Chinese with English abstract).
Yang, Q. X., 2008. Study on the fluxes in the Luzon Strait and turbulent mixing in the South China Sea. PhD thesis. Ocean University of China, Qingdao (in Chinese with English abstract).
Yaremchuk, M., and Qu, T. D., 2004. Seasonal variability of the large-scale currents near the coast of the Philippines. Journal of Physical Oceanography, 34 (4): 844–855.
Zhang, X. D., Zhang, G. Y., and Tong, K., 2004. Water mass analysis of the source area of Kuroshio. Marine Science Bulletin, 23 (1): 15–21 (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 thesis. Institute of Oceanology, Chinese Academy of Science, Qingdao (in Chinese).
Zhao, Y. P., Chen, Y. L., and Yang, L. S., 1994. The oceanic heat transport in the upper ocean of the northwestern Pacific Ocean in winter. Oceanologia et Limnologia Sinica, 25 (1): 9–14 (in Chinese with English abstract).
Zhou, H., Xu, J. P., Guo, P. F., and Shi, M. C., 2006. A summary on studies of western boundary current system in the North Pacific Ocean. Journal of Marine Sciences, 24 (2): 49–59 (in Chinese with English abstract).
Acknowledgements
The study is supported by the National Natural Science Foundation of China (Nos. 41676004, 41506034, 41376 001, 41376038, 41806123, 41430963), the Basic Scientific Fund for National Public Research Institutes of China (No. GY0213G02), the National Major Scientific Research Program (No. 2015CB954300), and the National Science and Technology Major Project (No. 2016ZX05057015).
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Ju, X., Ma, C., Xiong, X. et al. Circulation and Heat Flux along the Western Boundary of the North Pacific. J. Ocean Univ. China 19, 1–12 (2020). https://doi.org/10.1007/s11802-020-4168-z
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DOI: https://doi.org/10.1007/s11802-020-4168-z