La Ode M. Gunawan Giu, Agus S. Atmadipoera, Yuli Naulita, Dwiyoga Nugroho


The Indonesian Throughflow (ITF) is an inter-ocean Pacific-Indian current system that passes Indonesian Seas, such as via the primary path of Makassar Strait to Flores Sea and via the secondary path of Lifamatola Strait to Banda Sea. This study aims to investigate the structure and volume transport estimate of ITF Eastern Flores Sea (Flores) and Northern Banda Sea (Banda) derived from ocean model output of INDESO between 2008 and 2014. Structure of the ITF is analyzied by the average of current component vertically and transport volume estimated by cross-section at Banda and Flores sea. Time-series variability of ITF is analyzed  using band-pass filter and continuous wavelet transforms. The results showed that ITF Banda was characterized by flow dominantly towards south while ITF Flores depicted was flowing east along the North of Nusa Tenggara Islands. The vertical structure of ITF flow is intensified at a depth between 50 m and 150 m. The total volume transport estimate over the 7-year period from both ITF paths into the western Banda Sea is about 6.27 Sv (±3.81 Sv), which is a good agreement with previous model studies. Variations of transports ITF in Banda (Flores) is maximum during northwest (southeast) monsoon and minimum during southeast (northwest) monsoon. The variability of the ITF Banda is dominated intra-seasonal (ISV) and semi-annual periods (SAV), while the ITF Flores is annual period (AV).


Atmadipoera, A.S., R. Molcard, G. Madec, S. Wijffels, J. Sprintall, A. Koch-Larrouy, I. Jaya, & A. Supangat. 2009. Characteristics and variability of the indonesian throughflow water at the outflow straits. Deep-Sea Research part I, 56(11): 1942-1954.
Bendat, J.S. & A.G. Piersol. 2010. Random data analysis and measurement procedures. 4th ed. Wiley-Interscience Publication, John Wiley & Sons. New York. 640p.
Du, Y. & T. Qu. 2010. Three inflow pathways of the Indonesian throughflow asseen from the simple ocean data assimilation. J. Dynamics of Atmospheres and Oceans, 50(2): 233-256.
Emery, W.J. & R.E. Thomson. 2014. Data analysis methods in physical oceano-graphy. Third Edition. Elsevier, Wyman Street. MA (USA). 729pp.
Fieux, M., C. Andrie, D. Delecluse, A.G. Ilahude, A. Kartavtseff, F. Mantisi, R. Molcard, & J.C. Swallow. 1994. Measurements within the Pacific-Indian oceans throughflow region. Deep-Sea Research part I, 41(7): 1091–1130.
Gordon, A.L., A. Ffield, & A.G. Ilahude. 1994. Thermocline of the Flores and Banda Seas. J. Geophysical Research, 99(18): 235-242.
Gordon, A.L. & R.A. Fine. 1996. Pathways of water between the pasific and indian oceans in the indonesian seas. Nature, 379(6561): 146-149.
Gordon, A.L. & R.D. Susanto. 2001. Banda Sea surface-layer divergence. J. of Ocean Dynamic, 52(1): 2-10.‐001‐8172‐6
Gordon, A.L. 2005. Indonesian Sea. Oceanography, 18(4): 14-27.
Gordon. A.L., R.D. Susanto, A. Ffield, B.A. Huber, W. Pranowo, & S. Wirasantosa. 2008. Makassar Strait throughflow, 2004 to 2006. J. Geophysical Research, 35(L24605): 1-5.
Gordon, A.L., J. Sprintall, H.M. Van-Aken, R.D. Susanto, S. Wijffels, R. Molcard, A. Ffield, W. Pranowo, & S. Wirasantosa. 2010. The Indonesian throughflow during 2004–2006 as observed by the INSTANT program. Dynamics Atmospheres and Oceans, 50(2): 115-128.
Grinsted, A., J.C. Moore, & S. Javrejeva. 2004. Apllication of cross wavelet transform and wavelet coherence to geophysical time series. Nonlinear Processes in Geophysics, 11: 561-566.
Hautala, S.L., J. Sprintall, J. Potemra, A.G. Ilahude, J.C. Chong, W. Pandoe, & N. Bray. 2001. Velocity structure and transport of the Indonesian Throughflow in the major strait restricting flow into the Indian Ocean. J. Geophysical Research, 106(19): 19527-19546.
Hutahaen, W. & R.E. Wilson.1992. Upper Layer Circulation in the Banda Sea inResponse to the Onset Of Monsoon Winds. Marine Research Indonesia, 28: 81-95.
Iskandar, I., Y. Masumoto, K. Mizuno, H. Sasaki, A.K. Affandi, D. Setiabudidaya, & F. Syamsudin. 2014. Coherent intraseasonal oceanic variations in the eastern equatorial Indian Ocean and in the Lombok and Ombai Straits from observations and a high-resolution OGCM. J. Geophys. Res. Ocean. 119(4449): 615–630.
Liang, L., H. Xue, & Y. Shu. 2019. The Indonesian Throughflow and the Circulationin the Banda Sea: A Modeling Study. J. Geophysical Research: Oceans, 124:3089–3106.
Masoleh, V.C., A.S. Atmadipoera, & M. Purba . 2019. Ocean current signals propagation along the Outer Banda Arcs. IOP Conf. Ser. Earth Environ. Sci. 278(1): 1-7.
Mayer, B., P.E. Damm, T. Pohlmann, & S. Rizal. 2010. What is driving the ITF? An illumination of the Indonesianthroughflow with a numerical nested model system. J. Dynamics of Atmospheres and Oceans, 50(2): 301–312.
Quentel, E.X., M.A. Carton, M.A. Gutscer, & R. Hoobs. 2010. Detecting and characterizing mesoscale and hydrographic measurements in the Gulf of Cadiz, J. Geophysical Research, 37(6): 1-5.
Shinoda, T., W. Han, E.J. Metzger, & H.E. Hurlburt. 2012. Seasonal variation of the Indonesian throughflow in Makassar Strait. J. Phys. Oceanogr. 42(7): 1099–1123.
Sprintall, J., A.L. Gordon, R. Murtugudde, & R.D. Susanto. 2000. A semiannual Indian Ocean forced Kelvin wave observed in the Indonesian seas in May 1997. J. Geophys. Res. Ocean. 105(C7): 17217–17230.
Sprintall, J., S.E. Wijffels, R. Molcard, & I. Jaya. 2009. Direct estimates of the Indonesian throughflow entering the Indian Ocean: 2004–2006. J. Geophysical Research, 114(C07001): 1-9.
Sukresno, B. & I.W. Kasa. 2008. Dynamical analysis of Banda Sea concerning with El-Nino, Indonesian Throughflow and Monsoon by Using Satellite Data and Numerical Model. Ecotrophic, 3(2): 87-91.
Syamsudin, F., H.M. Van Aken, & A. Kaneko. 2010. Annual variation of the southern boundary current in the Banda Sea. Dynamics of Atmospheres and Oceans, 50(2): 129–139.
Torrence, C. & G.P. Compo. 1998. A practical guide to wavelet analysis. Bull. Am. Meteorol. Soc., 79: 61–78.<0061:APGTWA>2.0.CO;2
Tranchant, B., G. Reffray, E. Greiner, D. Nugroho, A. Koch-Larrouy, & P. Gaspa. 2016. Evaluation of an operational ocean modal configuration at 1/12° spatial resolution for the Indonesian seas. Oce. Phys. Geosci. Model. Dev. Disc., 8: 6611-6668.
Van-Aken, H.M., I.S. Brodjonegoro, & I. Jaya. 2009. The deep-water motion through the Lifamatola passage and its contribution to the Indonesian throughflow. Deep Sea Research partI, 56(8): 1203–1216.
Wijffels, S.E. & G. Meyers. 2004. An intersection of oceanic wave guides: variability in the Indonesian throughflow region. J. Phys. Oceanogr., 34: 1232–1253.<1232:AIOOWV>2.0.CO;2


La Ode M. Gunawan Giu (Primary Contact)
Agus S. Atmadipoera
Yuli Naulita
Dwiyoga Nugroho
GiuL. O. M. G., AtmadipoeraA. S., NaulitaY., & NugrohoD. (2020). VERTICAL SRUCTURE AND VARIABILITY OF INDONESIAN THROUGHFLOW (ITF) IN TO WESTERN BANDA SEA. Jurnal Ilmu Dan Teknologi Kelautan Tropis, 12(2), 455-469.

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