Abstract
The influences of the large-scale interannual variations in the eastern Indian Ocean on the variability of the Indonesian throughflow are investigated by using an ocean general circulation model, driven by the ERS satellite winds from July 1992 to June 1997. The empirical orthogonal function (EOF) analysis of the simulated surface dynamic height variability captures two dominant modes on an interannual time scale, which are quite consistent with the available observations. The first mode indicates large amplitude in the western tropical Pacific and has a strong relation to the El Niño events, while the second EOF exhibits the large amplitude in the eastern Indian Ocean. The simulated net Indonesian throughflow shows an interannual variation of amplitude of about 15 Sv, with large transport from the Pacific to the Indian Ocean during 1994/95 and small transport during 1992 and 1997. It turns out that the net throughflow variation shows a high correlation with the second EOF mode (r = 0.51) for the whole five-year simulation. On the other hand, the correlation with the first mode is rather low (r = −0.07). However, the relative importance of the EOF modes to the throughflow variability changes with time. The upper-layer transport above a depth of 230 m in the Indonesian archipelago is also affected by the second mode. The difference in the upper-layer transport across 1°S and 110°E generates warm water convergence/divergence with a magnitude of 4 Sv within the Indonesian Seas on the interannual time scale, which shows good correspondence with sea surface temperature variation averaged over the Indonesian archipelago.
Similar content being viewed by others
References
Bray, N. A., S. Hautala, J. Chong and J. Pariwono (1996): Large-scale sea level, thermocline, and wind variations in the Indonesian throughflow region. J. Geophys. Res., 101, 12,239–12,254.
Chambers, D. P., B. D. Tapley and R. H. Stewart (1999): Anomalous warming in the Indian Ocean coincident with El Niño. J. Geophys. Res., 104, 3035–3047.
Clarke, A. J. and X. Liu (1994): Interannual sea level in the northern and eastern Indian Ocean. J. Phys. Oceanogr., 24, 1224–1235.
Godfrey, J. S. (1989): A Sverdrup model of the depth-integrated flow for the world ocean, allowing for island circulations. Geophys. Astrophys. Fluid Dyn., 45, 89–112.
Godfrey, J. S. (1996): The effect of the Indonesian throughflow on ocean circulation and heat exchange with the atmosphere: A review. J. Geophys. Res., 101, 12,217–12,237.
Gordon, A. L. (1986): Interocean exchange of thermocline water. J. Geophys. Res., 91, 5037–5046.
Halpern, D., M. H. Freilich and R. A. Weller (1998): Arabian sea surface winds and ocean transports determined from ERS-1 scatterometer. J. Geophys. Res., 103, 7799–7805.
Masumoto, Y. and T. Yamagata (1996): Seasonal variations of the Indonesian throughflow in a general ocean circulation model. J. Geophys. Res., 101, 12,287–12,293.
Masumoto, Y., T. Kagimoto, M. Yoshida, M. Fukuda, N. Hirose and T. Yamagata (2001): Intraseasonal eddies in the Sulawesi Sea simulated in an ocean general circulation model. Geophys. Res. Lett., 28, 1631–1634.
Meyers, G. (1996): Variation of Indonesian throughflow and the El Niño-Southern Oscillation. J. Geophys. Res., 101, 12,475–12,482.
Meyers, G., R. J. Bailey and A. P. Worby (1995): Geostrophic transport of Indonesian throughflow. Deep-Sea Res., Part 1, 42, 1163–1174.
Murtugudde, R., A. J. Busalacchi and J. Beauchamp (1998): Seasonal-to-interannual effects of the Indonesian Throughflow on the tropical Indo-Pacific Basin. J. Geophys. Res., 103, 21,425–21,441.
Murtugudde, R., S. R. Signorini, J. R. Christian, A. J. Busalacchi, C. R. McClain and J. Picaut (1999): Ocean color variability of the tropical Indo-Pacific basin observed by SeaWIFS during 1997–1998. J. Geophys. Res., 104, 18,351–18,366.
Pacanowski, R. C. and S. G. H. Philander (1981): Parameterization of vertical mixing in numerical models of the tropical ocean. J. Phys. Oceanogr., 11, 1442–1451.
Pacanowski, R. C., K. Dixon and A. Rosati (1991): The GFDL modular ocean model user guide. The GFDL Ocean Group Technical Report No. 2, Geophysical Fluid Dynamics Laboratory, Princeton, U.S.A.
Potemra, J. T. and R. Lukas (1999): Seasonal to interannual modes of sea level variability in the western Pacific and eastern Indian Oceans. Geophys. Res. Lett., 26, 365–368.
Potemra, J. T., R. Lukas and G. T. Mitchum (1997): Large-scale estimation of transport from the Pacific to the Indian Ocean. J. Geophys. Res., 102, 27,795–27,812.
Qiu, B., M. Mao and Y. Kashino (1999): Intraseasonal variability in the Indo-Pacific throughflow and the regions surrounding the Indonesian Seas. J. Phys. Oceanogr., 29, 1599–1618.
Reynolds, R. W. and T. M. Smith (1994): Improved global sea surface temperature analyses using optimum interpolation. J. Climate, 7, 929–948.
Saji, N. H., B. N. Goswami, P. N. Vinayachandran and T. Yamagata (1999): A dipole mode in the tropical Indian Ocean. Nature, 401, 360–363.
Sprintall, J., J. Chong, F. Syamsudin, W. Morawitz, S. Hautala, N. Bray and S. Wijffels (1999): Dynamics of the South Java Current in the Indo-Australian basin. Geophys. Res. Lett., 26, 2493–2496.
Susanto, R. D., A. L. Gordon and Q. Zheng (2001): Upwelling along the coasts of Java and Sumatra and its relation to ENSO. Geophys. Res. Lett., 28, 1599–1602.
Wajsowicz, R. C. (1999): Models of the southeast Asian Seas. J. Phys. Oceanogr., 29, 986–1018.
Webster, P. J., A. M. Moore, J. P. Loschnigg and R. R. Leben (1999): Coupled ocean-atmosphere dynamics in the Indian Ocean during 1997–1998. Nature, 401, 356–360.
Wyrtki, K. (1961): Physical Oceanography of the Southeast Asian Waters. NAGA Report 2, Scripps Institution of Oceanography, 195 pp.
Wyrtki, K. (1987): Indonesian throughflow and the associated pressure gradient. J. Geophys. Res., 92, 12,941–12,946.
Wyrtki, K. (1989): Some thoughts about the west Pacific warm pool. Proc. of Western Pacific International Meeting and Workshop on TOGA COARE, 99–109.
Yamagata, T., K. Mizuno and Y. Masumoto (1996): Seasonal variations in the equatorial Indian Ocean and their impact on the Lombok throughflow. J. Geophys. Res., 101, 12,465–12,473.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Masumoto, Y. Effects of Interannual Variability in the Eastern Indian Ocean on the Indonesian Throughflow. Journal of Oceanography 58, 175–182 (2002). https://doi.org/10.1023/A:1015889004089
Issue Date:
DOI: https://doi.org/10.1023/A:1015889004089