Ocean Science Journal

, Volume 48, Issue 2, pp 149–160 | Cite as

Why was the 2008 Indian Ocean Dipole a short-lived event?

  • Iskhaq Iskandar
  • Muhammad Irfan
  • Fadli Saymsuddin


In this paper, the role of equatorial oceanic waves in affecting the evolution of the 2008 positive Indian Ocean Dipole (IOD) event was evaluated using available observations and output from a quasi-analytical linear wave model. It was found that the 2008 positive IOD was an early matured and abruptly terminated event: developed in April, matured in July, and diminished in September. During the development and the maturation of the 2008 positive IOD event, the wind-forced Rossby waves played a dominant role in generating zonal current anomalies in the western equatorial Indian Ocean, while a complex interplay between the wind-forced upwelling Kelvin waves and the eastern-boundary-generated Rossby waves accounted for most of the variability in the eastern basin. The latter induced eastward zonal current anomalies near the eastern boundary during the peak phase of the event. The 2008 positive IOD event was abruptly terminated in mid-July. We found that there were strong eastward zonal currents in mid-July, though the surface wind anomalies in the eastern basin continued to be westward (upwelling favorable). Our analysis shows that these eastward zonal currents mainly resulted from the easternboundary-generated upwelling Rossby waves, although the contribution from the wind-forced downwelling Kelvin waves was not negligible. These eastward zonal currents terminated the zonal heat advection and provided a favorable condition for surface heat flux to warm the eastern basin.

Key words

equatorial wave Indian Ocean Dipole Kelvin waves Rossby wave 


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Copyright information

© Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Iskhaq Iskandar
    • 1
    • 2
  • Muhammad Irfan
    • 1
  • Fadli Saymsuddin
    • 3
  1. 1.Department of Physics, Faculty of Mathematics and Natural SciencesUniversity of SriwijayaInderalaya, South SumatraIndonesia
  2. 2.Center for Geohazard and Climate Change Study, Faculty of Mathematics and Natural SciencesUniversity of SriwijayaInderalaya, South SumatraIndonesia
  3. 3.Agency for the Assessment and Application of TechnologyJakartaIndonesia

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