Ocean Dynamics

, Volume 58, Issue 3–4, pp 275–288 | Cite as

Physical processes contributing to the water mass transformation of the Indonesian Throughflow

  • Ariane Koch-LarrouyEmail author
  • Gurvan Madec
  • Daniele Iudicone
  • Agus Atmadipoera
  • Robert Molcard


The properties of the waters that move from the Pacific to the Indian Ocean via passages in the Indonesian archipelago are observed to vary with along-flow-path distance. We study an ocean model of the Indonesian Seas with reference to the observed water property distributions and diagnose the mechanisms and magnitude of the water mass transformations using a thermodynamical methodology. This model includes a key parameterization of mixing due to baroclinic tidal dissipation and simulates realistic water property distributions in all of the seas within the archipelago. A combination of air–sea forcing and mixing is found to significantly change the character of the Indonesian Throughflow (ITF). Around 6 Sv (approximately 1/3 the model net ITF transport) of the flow leaves the Indonesian Seas with reduced density. Mixing transforms both the intermediate depth waters (transforming 4.3 Sv to lighter density) and the surface waters (made denser despite the buoyancy input by air–sea exchange, net transformation = 2 Sv). The intermediate transformation to lighter waters suggests that the Indonesian transformation contributes significantly to the upwelling of cold water in the global conveyor belt. The mixing induced by the wind is not driving the transformation. In contrast, the baroclinic tides have a major role in this transformation. In particular, they are the only source of energy acting on the thermocline and are responsible for creating the homostad thermocline water, a characteristic of the Indonesian outflow water. Furthermore, they cool the sea surface temperature by between 0.6 and 1.5°C, and thus allow the ocean to absorb more heat from the atmosphere. The additional heat imprints its characteristics into the thermocline. The Indonesian Seas cannot only be seen as a region of water mass transformation (in the sense of only transforming water masses in its interior) but also as a region of water mass formation (as it modifies the heat flux and induced more buoyancy flux). This analysis is complemented with a series of companion numerical experiments using different representations of the mixing and advection schemes. All the different schemes diagnose a lack of significant lateral mixing in the transformation.


Indonesian Throughflow Water mass transformation Neutral density framework Thermodynamic Tidal mixing processes 



This work is part of the DRAKKAR project and is supported by MERCATOR-ocean (projects 100043 and 061396) and by the Marine Environment and Security for the European Area project (MERSEA, SIP3 CI 2003 502885). The ocean model integrations have been performed at the Institut de Développement et des Ressources en Informatique Scientifique (IDRIS, project 51140 and 1396).


  1. Alford M, Gregg MC (2001) Near-inertial mixing: modulation of shear, strain and microstructure at low latitude. J Geophys Res 106(C8):16,947–16,968. doi: 10.1029/2000JC000370 CrossRefGoogle Scholar
  2. Arief D, Murray SP (1996) Low-frequency fluctuations in the Indonesian Throughflow through Lombok Strait. J Geophys Res 101:12,455–12,464. doi: 10.1029/96JC00051 CrossRefGoogle Scholar
  3. Barnier B et al (2006) Impact of partial steps and momentum advection schemes in a global ocean circulation model at eddy permitting resolution. Ocean Dyn 56:377–378. doi: 10.1007/s10236-006-0090-1 CrossRefGoogle Scholar
  4. Blanke B, Delecluse P (1993) Variability of the tropical Atlantic ocean simulated by a general circulation model with two different mixed layer physics. J Phys Oceanogr 23:1363–1388. doi: 10.1175/1520-0485(1993)023<1363:VOTTAO>2.0.CO;2 CrossRefGoogle Scholar
  5. Cresswell G, Frische A, Peterson J, Quadfasel D (1993) Circulation in the Timor Sea. J Geophys Res 98:14379–14389. doi: 10.1029/93JC00317 CrossRefGoogle Scholar
  6. Ffield A, Gordon AL (1992) Vertical mixing in the Indonesian thermocline. J Phys Oceanogr 22:184–195. doi: 10.1175/1520-0485(1992)022<0184:VMITIT>2.0.CO;2 CrossRefGoogle Scholar
  7. Ffield A, Gordon A (1996) Tidal mixing signatures in the Indonesian seas. J Phys Oceanogr 26:1,924–1,937CrossRefGoogle Scholar
  8. Fieux M, Andrie C, Delecluse P, Ilahude AG, Kartavtseff A, Mantisi F, Molcard R, Swallow JC (1994) Measurements within the Pacific–Indian Oceans region. Deep-Sea Research. Part A 41:1091–1130CrossRefGoogle Scholar
  9. Fieux M, Molcard R, Ilahude AG (1996) Geostrophic transport of the Pacific–Indian Oceans Throughflow. J Geophys Res 101:12421–12432. doi: 10.1029/95JC03566 CrossRefGoogle Scholar
  10. Gerkema T, Lam F-PA, Maas LRM (2004) Internal tides in the Bay of Biscay: conversion rates and seasonal effects. Deep Sea Res Part II Top Stud Oceanogr 51:2995–3008. doi: 10.1016/j.dsr2.2004.09.012 CrossRefGoogle Scholar
  11. Gordon AL (2005) Oceanography of the Indonesian seas and their throughflow. Oceanography (Wash DC) 18:14–27Google Scholar
  12. Gordon AL, McClean J (1999) Thermohaline stratification of the Indonesian Seas—model and observations. J Phys Oceanogr 29:198–216. doi: 10.1175/1520-0485(1999)029<0198:TSOTIS>2.0.CO;2 CrossRefGoogle Scholar
  13. Hautala S, Reid JL, Bray NA (1996) The distribution and mixing of Pacific water masses in the Indonesian Seas. J Geophys Res 101:12,375–12,390. doi: 10.1029/96JC00037 CrossRefGoogle Scholar
  14. Hirst AC, Godfrey JS (1993) The role of the Indonesian Throughflow in a global ocean GCM. J Phys Oceanogr 23:1057–1086. doi: 10.1175/1520-0485(1993)023<1057:TROITI>2.0.CO;2 CrossRefGoogle Scholar
  15. Iudicone D, Madec G, McDougall TJ (2008a) Water-mass transformations in a neutral density framework and the key role of light penetration. J Phys Oceanogr 38:1357–1376 doi: 10.1175/2007JPO3464.1 CrossRefGoogle Scholar
  16. Iudicone D, Madec G, Blanke B, Speich S (2008b) The role of Southern ocean surface forcings and mixing in the Global conveyor. J Phys Oceanogr 38:1377–1400 doi: 10.1175/2008JPO3519.1 CrossRefGoogle Scholar
  17. Kamenkovich VM, Burnett WH, Gordon AI, Mellor GL (2003) The Pacific/Indian Ocean pressure difference and its influence on the Indonesian Seas circulation: Part II—The study with specified sea-surface heights. J Mar Res 61(5):613–634. doi: 10.1357/002224003771815972 CrossRefGoogle Scholar
  18. Koch-Larrouy A, Madec G, Bouruet-Aubertot P, Gerkema T, Bessières L, Molcard R (2007) On the transformation of Pacific Water into Indonesian Throughflow Water by internal tidal mixing. Geophys Res Lett 34:L04604. doi: 10.1029/2006GL028405 CrossRefGoogle Scholar
  19. Koch-Larrouy A, Madec G, Blanke B, Molcard R (2008) Quantification of the water paths and exchanges in the Indonesian archipelago. Ocean Dynamics (in press)Google Scholar
  20. Levitus S, Boyer TP, Conkright ME, O’Brien T, Antonov J, Stephens C, Stathoplos L, Johnson D, Gelfeld R (1998) NOAA Atlas NESDIS 18, WORLD OCEAN DATABASE (1998) Vol. 1: Introduction. U.S. Government Printing Office, Washington D.C., p 346Google Scholar
  21. Levy M, Estubier A, Madec G (2001) Choice of an advection scheme for biogeochemical ocean models. Geophys Res Lett 28(19):3725–3728. doi: 10.1029/2001GL012947 CrossRefGoogle Scholar
  22. Lyard F, et Le Provost C (2002) Energy budget of the tidal hydrodynamic model fes99. Appears in C. Le Provosts’ talk: “Ocean tides after a decade of high precision satellite altimetry”, SWT Jason 1, Arles, 2003Google Scholar
  23. Madec G (2008) NEMO = the OPA9 ocean engine. Note du Pole de Modélisation. Institut Pierre-Simon Laplace., 1:100 pp.
  24. Madec G, Delecluse P, Imbard M (1998) Opa8.1 ocean general circulation model reference manual. Note IPSL, 11:Paris VI, FranceGoogle Scholar
  25. McDougall TJ, Jackett DR (2005) An assessment of orthobaric density in the global ocean. J Phys Oceanogr 35:2054–2075. doi: 10.1175/JPO2796.1 CrossRefGoogle Scholar
  26. Molcard R, Fieux M, Ilahude AG (1996) The Indo-Pacific Throughflow in the Timor Passage. J Geophys Res 101:12411–12420. doi: 10.1029/95JC03565 CrossRefGoogle Scholar
  27. Molcard R, Fieux M, Syamsudin F (2001) The throughflow within Ombai Strait. Deep Sea Res Part I Oceanogr Res Pap 48:1237–1253. doi: 10.1016/S0967-0637(00)00084-4 CrossRefGoogle Scholar
  28. Potemra JT, Lukas R, Mitchum GT (1997) Large scale estimation of transport from the Pacific to the Indian Ocean. J Geophys Res 102:27795–27812. doi: 10.1029/97JC01719 CrossRefGoogle Scholar
  29. Polton JA, Smith JA, MacKinnon JA, Tejada-Martınez AE (2008) Rapid generation of high-frequency internal waves beneath a wind and wave forced oceanic surface mixed layer. Geophys Res Lett 35:L13602. doi: 10.1029/2008GL033856 CrossRefGoogle Scholar
  30. Purba M, Atmadipoera A (1992) On the study of dynamic topography in the southern Java–Sumba waters, paper presented at Third Ocean Research Institute–Indonesian Institute of Sciences (LIPI) Seminar on Marine Sciences, Oceanography for Fisheries, Tokyo, August 19–21Google Scholar
  31. St. Laurent LC, Simmons HL, Jayne SR (2002) Estimates of tidally driven enhanced mixing in the deep ocean. Geophys Res Lett 29:10.1029CrossRefGoogle Scholar
  32. Tréguier AM, Barnier B, de Miranda AP, Molines JM, Grima N, Imbard M, Madec G, Messager C, Reynaud T, Michel S (2001) An eddy-permitting model of the Atlantic circulation: evaluating open boundary conditions. J Geophys Res 106(C10):22,115–22,129CrossRefGoogle Scholar
  33. van Aken HM, Punjanan J, Saimima S (1988) Physical aspects of the flushing of the east Indonesian basins. Neth J Sea Res 22:315–339. doi: 10.1016/0077-7579(88)90003-8 CrossRefGoogle Scholar
  34. Wajsowicz RC, Schneider EK (2001) The Indonesian Throughflow’s effect on global climate determined from the COLA Coupled Climate System. J Climate 14:3,029–3,042Google Scholar
  35. Walin G (1982) On the relation between sea-surface heat flow and thermal circulation in the ocean. Tellus 34:187–195CrossRefGoogle Scholar
  36. Wijffels SE, Meyers G, Godfrey JS (2008) A twenty year average of the Indonesian Throughflow: regional currents and the interbasin exchange. J Phys Oceanogr, doi:  10.1175/JPO2008/3987.1
  37. Wyrtki K (1961) Physical oceanography of the southeast Asian Waters, NAGA Rep. 2, Scripps Institution of OceanographyGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Ariane Koch-Larrouy
    • 1
    Email author
  • Gurvan Madec
    • 1
  • Daniele Iudicone
    • 1
  • Agus Atmadipoera
    • 1
  • Robert Molcard
    • 1
  1. 1.Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN)ParisFrance

Personalised recommendations