Science China Earth Sciences

, Volume 61, Issue 6, pp 668–680 | Cite as

Multi-scale variability of the tropical Indian Ocean circulation system revealed by recent observations

  • Ke Huang
  • Dongxiao Wang
  • Weiqiang Wang
  • Qiang Xie
  • Ju Chen
  • Lingfang Chen
  • Gengxin Chen
Research Paper Special Topic: Carbon cycling in the China Seas


The tropical Indian Ocean circulation system includes the equatorial and near-equatorial circulations, the marginal sea circulation, and eddies. The dynamic processes of these circulation systems show significant multi-scale variability associated with the Indian Monsoon and the Indian Ocean dipole. This paper summarizes the research progress over recent years on the tropical Indian Ocean circulation system based on the large-scale hydrological observations and numerical simulations by the South China Sea Institute of Oceanology (SCSIO), Chinese Academy of Sciences. Results show that: (1) the wind-driven Kelvin and Rossby waves and eastern boundary-reflected Rossby waves regulate the formation and evolution of the Equatorial Undercurrent and the Equatorial Intermediate Current; (2) the equatorial wind-driven dynamics are the main factor controlling the inter-annual variability of the thermocline in the eastern Indian Ocean upwelling; (3) the equatorial waves transport large amounts of energy into the Bay of Bengal in forms of coastal Kelvin and reflected free Rossby waves. Several unresolved issues within the tropical Indian Ocean are discussed: (i) the potential effects of the momentum balance and the basin resonance on the variability of the equatorial circulation system, and (ii) the potential contribution of wind-driven dynamics to the life cycle of the eastern Indian Ocean upwelling. This paper also briefly introduces the international Indian Ocean investigation project of the SCSIO, which will advance the study of the multi-scale variability of the tropical Indian Ocean circulation system, and provide a theoretical and data basis to support marine environmental security for the countries around the Maritime Silk Road.


Equatorial undercurrent Equatorial intermediate current Eastern Indian Ocean upwelling Bay of Bengal circulation Multi-scale variability Equatorial wave dynamics Observation and simulation 


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This work was supported by the National Key Research and Development Program of China (Grant No. 2017YFC 1405100), the National Natural Science Foundation of China (Grant Nos. 41521005, 41476011, 41706027, 41676013), the Natural Science Foundation of Guangdong (Grant No. 2016A030310015), the Open Fund of the Key Laboratory of Ocean Circulation and Waves, Chinese Academy of Sciences (Grant No. KLOCW1604), the Open Fund of the State Key Laboratory of Tropical Oceanography (Grant No. LTOZZ1702), the MEL Visiting Fellowship (Grant No. MELRS1640) and the Guangzhou Science and Technology Foundation (Grant No. 201804010133).


  1. Anderson D L T, Carrington D J. 1993. Modeling interannual variability in the Indian Ocean using momentum fluxes from the operational weather analyses of the United Kingdom Meteorological Office and European Centre for Medium Range Weather Forecasts. J Geophys Res, 98: 12483–12499CrossRefGoogle Scholar
  2. Arief D, Murray S P. 1996. Low-frequency fluctuations in the Indonesian throughflow through Lombok Strait. J Geophys Res, 101: 12455–12464CrossRefGoogle Scholar
  3. Babu M T, Sarma Y V B, Murty V S N, Vethamony P. 2003. On the circulation in the Bay of Bengal during Northern spring inter-monsoon (March–April 1987). Deep-Sea Res Part II-Top Stud Oceanogr, 50: 855–865CrossRefGoogle Scholar
  4. Balmaseda M A, Trenberth K E, Källén E. 2013. Distinctive climate signals in reanalysis of global ocean heat content. Geophys Res Lett, 40: 1754–1759CrossRefGoogle Scholar
  5. Brandt P, Claus M, Greatbatch R J, Kopte R, Toole J M, Johns W E, Böning C W. 2016. Annual and semiannual cycle of equatorial Atlantic circulation associated with Basin-Mode resonance. J Phys Oceanogr, 46: 3011–3029CrossRefGoogle Scholar
  6. Bograd S J, Schroeder I, Sarkar N, Qiu X, Sydeman W J, Schwing F B. 2009. Phenology of coastal upwelling in the California Current. Geophys Res Lett, 36: L01602CrossRefGoogle Scholar
  7. Chen G X, Wang D X, Hou Y J. 2012. The features and interannual variability mechanism of mesoscale eddies in the Bay of Bengal. Cont Shelf Res, 47: 178–185CrossRefGoogle Scholar
  8. Chen G X, Han W Q, Li Y L, Wang D, McPhaden M J. 2015a. Seasonal-tointerannual time-scale dynamics of the equatorial undercurrent in the Indian Ocean. J Phys Oceanogr, 45: 1532–1553CrossRefGoogle Scholar
  9. Chen G X, Han W, Li Y, Wang D, Shinoda T. 2015b. Intraseasonal variability of upwelling in the equatorial Eastern Indian Ocean. J Geophys Res-Oceans, 120: 7598–7615CrossRefGoogle Scholar
  10. Chen G X, Han W, Li Y, Wang D. 2016a. Interannual variability of equatorial Eastern Indian Ocean upwelling: Local versus remote forcing. J Phys Oceanogr, 46: 789–807CrossRefGoogle Scholar
  11. Chen G X, Han W, Shu Y, Li Y, Wang D, Xie Q. 2016b. The role of Equatorial Undercurrent in sustaining the Eastern Indian Ocean upwelling. Geophys Res Lett, 43: 6444–6451CrossRefGoogle Scholar
  12. Chen G X, Han W, Li Y, McPhaden M J, Chen J, Wang W, Wang D. 2017. Strong intraseasonal variability of meridional currents near 5°N in the Eastern Indian Ocean: Characteristics and causes. J Phys Oceanogr, 47: 979–998CrossRefGoogle Scholar
  13. Cheng X H, McCreary J P, Qiu B, Qi Y Q, Du Y. 2017. Intraseasonal-tosemiannual variability of sea-surface height in the eastern equatorial Indian Ocean and southern Bay of Bengal. J Geophys Res-Oceans, 122: 4051–4067CrossRefGoogle Scholar
  14. Clarke A J, Liu X. 1993. Observations and dynamics of semiannual and annual sea levels near the Eastern Equatorial Indian Ocean boundary. J Phys Oceanogr, 23: 386–399CrossRefGoogle Scholar
  15. Delcroix T, Henin C. 1988. Observations of the equatorial intermediate current in the Western Pacific Ocean (165°E). J Phys Oceanogr, 18: 363–366CrossRefGoogle Scholar
  16. Duan Y, Liu L, Han G, Liu H, Yu W, Yang G, Wang H, Wang H, Liu Y, Zahid Y, Waheed H. 2016. Anomalous behaviors of Wyrtki Jets in the equatorial Indian Ocean during 2013. Sci Rep, 6: 29688CrossRefGoogle Scholar
  17. Eriksen C C. 1981. Deep currents and their interpretation as equatorial waves in the Western Pacific Ocean. J Phys Oceanogr, 11: 48–70CrossRefGoogle Scholar
  18. Fischer J, Schott F A. 1997. Seasonal transport variability of the deep western boundary current in the equatorial Atlantic. J Geophys Res, 102: 27751–27769CrossRefGoogle Scholar
  19. Firing E. 1987. Deep zonal currents in the central equatorial Pacific. J Mar Res, 45: 791–812CrossRefGoogle Scholar
  20. Gill A E. 1982. Atmosphere-Ocean Dynamics. Orlando: AcademicGoogle Scholar
  21. Godfrey J S, Hu R J, Schiller A, Fiedler R. 2007. Explorations of the annual mean heat budget of the tropical Indian Ocean. Part I: Studies with an idealized model. J Clim, 20: 3210–3228Google Scholar
  22. Gouriou Y, Delcroix T, Eldin G. 2006. Upper and intermediate circulation in the western equatorial Pacific Ocean in October 1999 and April 2000. Geophys Res Lett, 33: L10603CrossRefGoogle Scholar
  23. Han W Q, McCreary Jr J P, Anderson D L T, Mariano A J. 1999. Dynamics of the eastern surface jets in the equatorial Indian Ocean. J Phys Oceanogr, 29: 2191–2209CrossRefGoogle Scholar
  24. Han W, Webster P, Lukas R, Hacker P, Hu A. 2004. Impact of atmospheric intraseasonal variability in the Indian Ocean: Low-frequency rectification in equatorial surface current and transport. J Phys Oceanogr, 34: 1350–1372CrossRefGoogle Scholar
  25. Han W Q, McCreary J P, Masumoto Y, Vialard J, Duncan B. 2011. Basin resonances in the equatorial Indian Ocean. J Phys Oceanogr, 41: 1252–1270CrossRefGoogle Scholar
  26. Hood R R, Bange H W, Beal L, Beckley L E, Burkill P, Cowie G L, D’Adamo N, Ganssen G, Hendon H, Hermes J, Honda M, McPhaden M, Roberts M, Singh S, Urban E, Yu W. 2015. The Second International Indian Ocean Expedition (IIOE-2): A basin-wide research program-Science Plan (2015–2020). Delaware: SCOR Newark. 101Google Scholar
  27. Iskandar I, Masumoto Y, Mizuno K. 2009. Subsurface equatorial zonal current in the eastern Indian Ocean. J Geophys Res, 114: C06005CrossRefGoogle Scholar
  28. Kessler W S, McCreary J P. 1993. The annual wind-driven rossby wave in the subthermocline equatorial Pacific. J Phys Oceanogr, 23: 1192–1207CrossRefGoogle Scholar
  29. Knox R A. 1976. On a long series of measurements of Indian Ocean equatorial currents near Addu Atoll. Deep Sea Res Oceanogr Abstr, 23: 211–IN1CrossRefGoogle Scholar
  30. Krishnan R, Swapna P. 2009. Significant influence of the boreal summer monsoon flow on the Indian Ocean response during dipole events. J Clim, 22: 5611–5634CrossRefGoogle Scholar
  31. Kuswardani. 2012. The development of a wave-tide-circulation coupled model and its upwelling simulation application in the Indonesian Sea. Dissertation for Doctoral Degree. Qingdao: Ocean University of ChinaGoogle Scholar
  32. Li Y, Han W, Shinoda T, Wang C, Ravichandran M, Wang J W. 2014. Revisiting the wintertime intraseasonal SST variability in the tropical south Indian Ocean: Impact of the Ocean interannual variation. J Phys Oceanogr, 44: 1886–1907CrossRefGoogle Scholar
  33. Lukas R, Firing E. 1985. The annual rossby wave in the central equatorial Pacific Ocean. J Phys Oceanogr, 15: 55–67CrossRefGoogle Scholar
  34. Luyten J R, Roemmich D H. 1982. Equatorial currents at semi-annual period in the Indian Ocean. J Phys Oceanogr, 12: 406–413CrossRefGoogle Scholar
  35. Masson S, Boulanger J P, Menkes C, Delecluse P, Yamagata T. 2004. Impact of salinity on the 1997 Indian Ocean dipole event in a numerical experiment. J Geophys Res, 109: C02002CrossRefGoogle Scholar
  36. McCreary J P. 1980. Modeling wind-driven ocean circulation. Hawaii Institute of Geophysics Tech. HIG-80-3, 64Google Scholar
  37. McCreary J P. 1981. A linear stratified ocean model of the coastal undercurrent. Philos Trans R Soc A-Math Phys Eng Sci, 302: 385–413CrossRefGoogle Scholar
  38. McPhaden M J, Meyers G, Ando K, Masumoto Y, Murty V S N, Ravichandran M, Syamsudin F, Vialard J, Yu L, Yu W. 2009. RAMA: The research moored array for African-Asian-Australian Monsoon analysis and prediction. Bull Amer Meteorol Soc, 90: 459–480CrossRefGoogle Scholar
  39. McPhaden M J, Wang Y, Ravichandran M. 2015. Volume transports of the Wyrtki jets and their relationship to the Indian Ocean Dipole. J Geophys Res-Oceans, 120: 5302–5317CrossRefGoogle Scholar
  40. Nagura M, McPhaden M J. 2016. Zonal propagation of near-surface zonal currents in relation to surface wind forcing in the equatorial Indian Ocean. J Phys Oceanogr, 46: 3623–3638CrossRefGoogle Scholar
  41. O’Brien J J, Hurlburt H E. 1974. Equatorial jet in the Indian Ocean: Theory. Science, 184: 1075–1077CrossRefGoogle Scholar
  42. Ogata T, Xie S P. 2011. Semiannual cycle in zonal wind over the equatorial Indian Ocean. J Clim, 24: 6471–6485CrossRefGoogle Scholar
  43. Philander S G H. 1978. Forced oceanic waves. Rev Geophys, 16: 15CrossRefGoogle Scholar
  44. Philander S G H, Chao Y. 1991. On the contrast between the seasonal cycles of the equatorial Atlantic and Pacific Oceans. J Phys Oceanogr, 21: 1399–1406CrossRefGoogle Scholar
  45. Reppin J, Schott F A, Fischer J, Quadfasel D. 1999. Equatorial currents and transports in the upper central Indian Ocean: Annual cycle and interannual variability. J Geophys Res, 104: 15495–15514CrossRefGoogle Scholar
  46. Saji N H, Goswami B N, Vinayachandran P N, Yamagata T. 1999. A dipole mode in the tropical Indian Ocean. Nature, 401: 360–363Google Scholar
  47. Sanilkumar K V, Kuruvilla T V, Jogendranath D, Rao R R. 1997. Observations of the Western Boundary Current of the Bay of Bengal from a hydrographic survey during March 1993. Deep-Sea Res Part IOceanogr Res Pap, 44: 135–145CrossRefGoogle Scholar
  48. Schott F, Fischer J, Garternicht U, Quadfasel D. 1997. Summer monsoon response of the Northern Somali Current, 1995. Geophys Res Lett, 24: 2565–2568CrossRefGoogle Scholar
  49. Schott F A, McCreary Jr J P. 2001. The monsoon circulation of the Indian Ocean. Prog Oceanogr, 51: 1–123CrossRefGoogle Scholar
  50. Schott F A, Xie S P, McCreary Jr. J P. 2009. Indian Ocean circulation and climate variability. Rev Geophys, 47: RG1002CrossRefGoogle Scholar
  51. Shankar D, McCreary J P, Han W, Shetye S R. 1996. Dynamics of the East India Coastal Current: 1. Analytic solutions forced by interior Ekman pumping and local alongshore winds. J Geophys Res, 101: 13975–13991Google Scholar
  52. Shu Y Q, Xue H J, Wang D X, Chai F, Xie Q, Yao J, Xiao J. 2014. Meridional overturning circulation in the South China Sea envisioned from the high-resolution global reanalysis data GLBa0.08. J Geophys Res-Oceans, 119: 3012–3028CrossRefGoogle Scholar
  53. Sprintall J, Gordon A L, Murtugudde R, Susanto R D. 2000. A semiannual Indian Ocean forced Kelvin wave observed in the Indonesian seas in May 1997. J Geophys Res, 105: 17217–17230CrossRefGoogle Scholar
  54. Susanto R D, Gordon A L, Zheng Q. 2001. Upwelling along the coasts of Java and Sumatra and its relation to ENSO. Geophys Res Lett, 28: 1599–1602CrossRefGoogle Scholar
  55. Swallow J. 1967. The equatorial undercurrent in the western Indian Ocean in 1964. Stud Trop Oceanogr, 5: 15–36Google Scholar
  56. Swapna P, Krishnan R. 2008. Equatorial undercurrents associated with Indian Ocean Dipole events during contrasting summer monsoons. Geophys Res Lett, 35: L14S04CrossRefGoogle Scholar
  57. Thompson B, Gnanaseelan C, Salvekar P S. 2006. Variability in the Indian Ocean circulation and salinity and its impact on SST anomalies during dipole events. J Mar Res, 64: 853–880CrossRefGoogle Scholar
  58. Valsala V, Maksyutov S, Murtugudde R. 2010. Possible interannual to interdecadal variabilities of the Indonesian throughflow water pathways in the Indian Ocean. J Geophys Res, 115: C10016CrossRefGoogle Scholar
  59. Wang D X, Wu G X, Xu J J. 1999. Decadal ocean variability and its dynamical interpretation in tropical Indian Ocean (in Chinese). Chin Sci Bull, 44: 1226–1232Google Scholar
  60. Wang J, Yuan D. 2015. Roles of western and eastern boundary reflections in the interannual sea level variations during negative Indian Ocean dipole events. J Phys Oceanogr, 45: 1804–1821CrossRefGoogle Scholar
  61. Webster P J, Moore A M, Loschnigg J P, Leben R R. 1999. Coupled oceanatmosphere dynamics in the Indian Ocean during 1997–98. Nature, 401: 356–360CrossRefGoogle Scholar
  62. Wei F Y. 2002. Climate Statistical Diagnosis and Prediction Technology. Beijing: Meteorological Press. 343Google Scholar
  63. Wyrtki K. 1973. An equatorial jet in the Indian Ocean. Science, 181: 262–264CrossRefGoogle Scholar
  64. Yu L, O’Brien J J, Yang J. 1991. On the remote forcing of the circulation in the Bay of Bengal. J Geophys Res, 96: 20449CrossRefGoogle Scholar
  65. Yuan D L, Han W Q. 2006. Roles of equatorial waves and western boundary reflection in the seasonal circulation of the equatorial Indian Ocean. J Phys Oceanogr, 36: 930–944CrossRefGoogle Scholar

Copyright information

© Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Ke Huang
    • 1
    • 4
  • Dongxiao Wang
    • 1
  • Weiqiang Wang
    • 1
    • 3
  • Qiang Xie
    • 1
    • 2
    • 3
  • Ju Chen
    • 1
  • Lingfang Chen
    • 2
  • Gengxin Chen
    • 1
  1. 1.State Key Laboratory of Tropical Oceanography, South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhouChina
  2. 2.Institute of Deep Sea Science and EngineeringChinese Academy of SciencesSanyaChina
  3. 3.Laboratory for Regional Oceanography and Numerical ModelingQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
  4. 4.State Key Laboratory of Marine Environmental ScienceXiamen UniversityXiamenChina

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