Journal of Oceanography

, Volume 72, Issue 2, pp 313–326 | Cite as

Impact of intraseasonal salinity variations on sea surface temperature in the eastern equatorial Indian Ocean

  • T. HoriiEmail author
  • I. Ueki
  • K. Ando
  • T. Hasegawa
  • K. Mizuno
  • A. Seiki
Original Article


A systematic salinity variation in the upper ocean may have an impact on air–sea interactions through a change in ocean stratification and hence on the oceanic response to atmospheric forcing. In this study, we evaluate the possible role of salinity variation in the oceanic response to intraseasonal atmospheric forcing, by investigating the ocean temperature and salinity variation in the eastern Indian Ocean. We primarily used data from three moored buoys located in an area with a large salinity gradient in the eastern equatorial Indian Ocean. Observed upper-layer salinity variation shows significant spectral peaks at intraseasonal time scales. Analysis indicates that surface zonal currents mainly produce the intraseasonal salinity variation through zonal advection with these currents induced by the Madden–Julian Oscillation (MJO). Composite analyses focusing on 35 significant MJO events during 2002–2012 confirmed that intraseasonal atmospheric forcing resulted in variations of net surface heat flux, mixed layer temperature and salinity, and mixed layer depth. We also found that a large salinity change could increase the amplitude of mixed layer temperature variation by changing the mixed layer depth. A possible process by which intraseasonal salinity variation could affect sea surface temperature is discussed.


Surface salinity Ocean stratification Eastern Indian Ocean Mixed layer temperature Madden–Julian oscillation RAMA buoy 



We thank all of the members of the R/V Mirai and the data processing team of the Triangle Trans-Ocean Buoy Network (TRITON) buoy cruise operations for their data management. We also thank the US National Oceanic and Atmospheric Administration (NOAA)/Pacific Marine Environmental Laboratory (PMEL) and National Institute of Oceanography (NIO) for providing RAMA buoy data, and the NOAA-Cooperative Institute for Research in Environmental Sciences (CIRES) Earth System Research Laboratory (ESRL)/Physical Sciences Division (PSD) for providing SST data and reanalysis flux products. The TropFlux data were produced through a collaboration between Laboratoire d’Océanographie: Expérimentation et Approches Numériques (LOCEAN) from Institut Pierre Simon Laplace (IPSL, Paris, France) and the National Institute of Oceanography/CSIR (NIO, Goa, India), and it was supported by the Institut de Recherche pour le Développement (IRD, France). We thank two anonymous reviewers for valuable comments and suggestions.


  1. Akima H (1970) A new method of interpolation and smooth curve fitting based on local procedures. J Assoc Comput Mach 17:589–602CrossRefGoogle Scholar
  2. Bergman JW, Hendon HH, Weickmann KM (2001) Intraseasonal air-sea interactions at the onset of El Niño. J Climate 14:1702–1719CrossRefGoogle Scholar
  3. Clark NE, Eber L, Laurs RM, Renner JA, Saur JFT (1974) Heat exchange between ocean and atmosphere in the eastern North Pacific for 1961–1971. NOAA Tech. Rep. NMRS SSRF-682, p 108Google Scholar
  4. de Boyer Montégut C, Madec G, Fischer AS, Lazar A, Iudicone D (2004) Mixed layer depth over the global ocean: an examination of profile data and a profile-based climatology. J Geophys Res 109:C12003. doi: 10.1029/2004JC002378 CrossRefGoogle Scholar
  5. Donguy JR, Meyers G (1996) Seasonal variations of sea-surface salinity and temperature in the tropical Indian Ocean. Deep Sea Res (I) 43:117–138CrossRefGoogle Scholar
  6. Drushka K, Sprintall J, Gille ST, Wijffels S (2012) In situ observations of Madden–Julian Oscillation mixed layer dynamics in the Indian and Western Pacific Oceans. J Clim 25:2306–2328CrossRefGoogle Scholar
  7. Drushka K, Sprintall J, Gille ST (2014) Subseasonal variations in salinity and barrier-layer thickness in the eastern equatorial Indian Ocean. J Geophys Res Oceans 119:805–823. doi: 10.1002/2013JC009422 CrossRefGoogle Scholar
  8. Duchon CE (1979) Lanczos filtering in one and two dimensions. J Appl Meteorol 18(8):1016–1022CrossRefGoogle Scholar
  9. Grunseich G, Subrahmanyam B, Arguez A (2011) Influence of the Madden–Julian Oscillation on sea surface salinity in the Indian Ocean. Geophys Res Lett 38:L17605. doi: 10.1029/2011GL049047 CrossRefGoogle Scholar
  10. Grunseich G, Subrahmanyam B, Wang B (2013) The Madden–Julian oscillation detected in Aquarius salinity observations. Geophys Res Lett 40:5461–5466. doi: 10.1002/2013GL058173 CrossRefGoogle Scholar
  11. Guan B, Lee T, Halkides DJ, Waliser DE (2014) Aquarius surface salinity and the Madden-Julian Oscillation: the role of salinity in surface layer density and potential energy. Geophys Res Lett 41:2858–2869. doi: 10.1002/2014GL059704 CrossRefGoogle Scholar
  12. Han W, Yuan D, Liu WT, Halkides DJ (2007) Intraseasonal variability of Indian Ocean sea surface temperature during boreal winter: Madden-Julian Oscillation versus submonthly forcing and processes. J Geophys Res 112:C04001. doi: 10.1029/2006JC003791 Google Scholar
  13. Hase H, Masumoto Y, Kuroda Y, Mizuno K (2008) Semiannual variability in temperature and salinity observed by Triangle Trans-Ocean Buoy Network (TRITON) buoys in the eastern tropical Indian Ocean. J Geophys Res 113:C01016. doi: 10.1029/2006JC004026 Google Scholar
  14. Horii T, Ueki I, Ando K, Mizuno K (2013) Eastern Indian Ocean warming associated with the negative Indian Ocean dipole: a case study of the 2010 event. J Geophys Res Oceans 118:536–549. doi: 10.1002/jgrc.20071 CrossRefGoogle Scholar
  15. Hosoda S, Ohira T, Nakamura T (2008) A monthly mean dataset of global oceanic temperature and salinity derived from Argo float observations. JAMSTEC Rep Res Dev 8:47–59CrossRefGoogle Scholar
  16. Huffman GJ, Bolvin DT, Nelkin EJ, Wolff DB, Adler RF, Gu G, Hong Y, Bowman KP, Stocker EF (2007) The TRMM multi-satellite precipitation analysis: quasi-global, multi-year, combined-sensor precipitation estimates at fine scale. J Hydrometeorol 8(1):38–55. doi: 10.1175/JHM560.1 CrossRefGoogle Scholar
  17. Iskandar I, Masumoto Y, Mizuno K (2009) Subsurface equatorial zonal current in the eastern Indian Ocean. J Geophys Res 114:C06005. doi: 10.1029/2008JC005188 Google Scholar
  18. Jensen TG (2001) Arabian Sea and Bay of Bengal exchange of salt and tracers in an ocean model. Geophys Res Lett 28:3967–3970CrossRefGoogle Scholar
  19. Kalnay E et al (1996) The NCEP/NCAR 40-year reanalysis project. Bull Ame Meteor Soc 77:437–471CrossRefGoogle Scholar
  20. Kuroda Y (2002) TRITON: present status and future plan. TOCS Rep 5 p 77 JAMSTEC Kanagawa Japan.Google Scholar
  21. Li Y, Han W, Lee T (2015) Intraseasonal sea surface salinity variability in the equatorial Indo-Pacific Ocean induced by Madden-Julian oscillations. J Geophys Res. doi: 10.1002/2014JC010647 Google Scholar
  22. Liebmann B, Smith CA (1996) Description of a complete (interpolated) outgoing longwave radiation dataset. Bull Am Meteor Soc 77:1275–1277Google Scholar
  23. Lukas R, Lindstrom E (1991) The mixed layer of the western equatorial Pacific Ocean. J Geophys Res 96:3343–3357CrossRefGoogle Scholar
  24. Madden RA, Julian PR (1972) Description of global scale circulation cell in the tropics with a 40–50 day period. J Atmos Sci 29:1109–1123CrossRefGoogle Scholar
  25. Madden RA, Julian PR (1994) Observations of the 40–50 day tropical oscillation: a review. Mon Weather Rev 122:814–837CrossRefGoogle Scholar
  26. Maloney E, Sobel A (2004) Surface fluxes and ocean coupling in the tropical intraseasonal oscillation. J Climate 17:3717–3720Google Scholar
  27. Masson SP, Delecluse P, Boulanger JP, Menkes C (2002) A model study of the seasonal variability and formation mechanisms of the barrier layer in the eastern equatorial Indian Ocean. J Geophys Res 107(C12):8017. doi: 10.1029/2001JC000832 Google Scholar
  28. Masumoto Y, Hase H, Kuroda Y, Matsuura H (2005) Current variability in the Indian Ocean. Geophys Res Lett 32:L02607. doi: 10.1029/2004GL021896 CrossRefGoogle Scholar
  29. Matthews A, Singhruck P, Heywood K (2010) Ocean temperature and salinity components of the Madden-Julian oscillation observed by Argo floats. Clim Dyn 35(7–8):1149–1168. doi: 10.1007/s00382-009-0631-7 CrossRefGoogle Scholar
  30. McPhaden MJ, Foltz G (2013) Intraseasonal variations in the surface layer heat balance of the central equatorial Indian Ocean: the importance of zonal advection and vertical mixing. Geophys Res Lett 40:2737–2741. doi: 10.1002/grl.50536 CrossRefGoogle Scholar
  31. McPhaden MJ, Meyers G, Ando K, Masumoto Y, Murty VSN, 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(4):459–480CrossRefGoogle Scholar
  32. Nagura M, McPhaden MJ (2012) The dynamics of wind-driven intraseasonal variability in the equatorial Indian Ocean. J Geophys Res 117:C02001. doi: 10.1029/2011JC007405 Google Scholar
  33. Paulson CA, Simpson JJ (1977) Irradiance measurements in the upper ocean. J Phys Oceanogr 7:952–956CrossRefGoogle Scholar
  34. Praveen Kumar B, Vialard J, Lengaigne M, Murty V, McPhaden MJ (2012) Tropflux: air-sea fluxes for the global tropical oceans–description and evaluation. Clim Dyn 38:1521–1543. doi: 10.1007/s00382-012-1455-4 CrossRefGoogle Scholar
  35. Qiu YW, Cai W, Li L, Guo X (2012) Argo profiles variability of barrier layer in the tropical Indian Ocean and its relationship with the Indian Ocean Dipole. Geophys Res Lett 39:L08605. doi: 10.1029/2012GL051441 CrossRefGoogle Scholar
  36. Rao RR, Sivakumar R (2003) Seasonal variability of sea surface salinity and salt budget of the mixed layer of the north Indian Ocean. J Geophys Res. doi: 10.1029/2001JC000907 Google Scholar
  37. Rao SA, Yamagata T (2004) Abrupt termination of Indian Ocean dipole events in response to intraseasonal disturbances. Geophys Res Lett 31:L19306. doi: 10.1029/2004GL020842 CrossRefGoogle Scholar
  38. Reynolds RW, Smith TM, Liu C, Chelton DB, Casey KS, Schlax MG (2007) Daily high-resolution-blended analyses for sea surface temperature. J Clim 20:5473–5496CrossRefGoogle Scholar
  39. Salby ML, Hendon HH (1994) Intraseasonal behavior of clouds, temperature, and motion in the tropics. J Atmos Sci 51:2207–2224CrossRefGoogle Scholar
  40. Schiller A, Godfrey J (2003) Indian Ocean intraseasonal variability in an ocean general circulation model. J Clim 16:21–39CrossRefGoogle Scholar
  41. Schott FA, Xie S-P, McCreary JP Jr (2009) Indian Ocean circulation and climate variability. Rev Geophys 47:RG1002. doi: 10.1029/2007RG000245 Google Scholar
  42. Shinoda T, Hendon HH (1998) Mixed layer modeling of intraseasonal variability in the tropical western Pacific and Indian Oceans. J Clim 11:2668–2685CrossRefGoogle Scholar
  43. Sprintall J, Tomczak M (1992) Evidence of the barrier layer in the surface layer of the tropics. J Geophys Res 97(C5):7305–7316CrossRefGoogle Scholar
  44. Takayabu YN, Iguchi T, Kachi M, Shibata A, Kanzawa H (1999) An impact of a Madden-Julian oscillation on the abrupt termination of the 1997–98 El Niño. Nature 402:279–282CrossRefGoogle Scholar
  45. Vialard J, Foltz G, McPhaden MJ, Duvel JP, de Boyer Montégut C (2008) Strong Indian Ocean sea surface temperature signals associated with the Madden-Julian Oscillation in late 2007 and early 2008. Geophys Res Lett 35:L19608. doi: 10.1029/2008GL035238 CrossRefGoogle Scholar
  46. Waliser DE, Lau K, Kim J (1999) The influence of coupled sea surface temperatures on the Madden-Julian oscillation: a model perturbation experiment. J Atmos Sci 56:333–358CrossRefGoogle Scholar
  47. Waliser DE, Murtugudde R, Lucas LE (2003) Indo-Pacific Ocean response to atmospheric intraseasonal variability. Part I: austral summer and the Madden–Julian oscillation. J Geophys Res 108:3160. doi: 10.1029/2002JC001620 CrossRefGoogle Scholar
  48. Wheeler M, Hendon H (2004) An all-season real-time multivariate MJO index: development of an index for monitoring and prediction. Mon Weather Rev 132:1917–1932CrossRefGoogle Scholar
  49. Woolnough SJ, Vitart F, Balmaseda M (2007) The role of the ocean in the Madden-Julian oscillation: implications for MJO prediction. Quart J Roy Meteor Soc 133:117–128CrossRefGoogle Scholar
  50. Wyrtki K (1973) An equatorial jet in the Indian Ocean. Science 181:262–264CrossRefGoogle Scholar
  51. Zhang YC, Rossow WB, Lacis AA, Oinas V, Mishchenko MI (2004) Calculation of radiative fluxes from the surface to top of atmosphere based on ISCCP and other global data sets: refinements of the radiative transfer model and the input data. J Geophys Res 109:D19105. doi: 10.1029/2003JD004457 CrossRefGoogle Scholar
  52. Zhang Y, Du Y, Zheng S, Yang Y, Cheng X (2013) Impact of Indian Ocean Dipole on the salinity budget in the equatorial Indian Ocean. J Geophys Res Oceans 118:4911–4923. doi: 10.1002/jgrc.20392 CrossRefGoogle Scholar

Copyright information

© The Oceanographic Society of Japan and Springer Japan 2015

Authors and Affiliations

  • T. Horii
    • 1
    Email author
  • I. Ueki
    • 1
  • K. Ando
    • 1
  • T. Hasegawa
    • 1
  • K. Mizuno
    • 1
  • A. Seiki
    • 2
  1. 1.Research and Development Center for Global Change (RCGC), Strategic Research and Development AreaJapan Agency for Marine-Earth Science and Technology (JAMSTEC)YokosukaJapan
  2. 2.Department of Coupled Ocean–Atmosphere–Land Processes ResearchJapan Agency for Marine-Earth Science and Technology (JAMSTEC)YokosukaJapan

Personalised recommendations