Coupled Ocean-Atmosphere Mode in the Tropical Indian Ocean during 2011

Coupled ocean-atmosphere mode in the tropical Indian Ocean, so-called the Indian Ocean Dipole (IOD), occurred during boreal summer to fall 2011. In this study, data from satellite observations and atmospheric reanalysis datasets together with data from ocean current mooring were used to evaluate the evolution of the 2011 IOD event. It is shown that the 2011 IOD was a weak and short-lived event. It developed in July, peaked in September, decayed in October and terminated in November. During the peak phase, maximum negative sea surface temperature anomaly off Sumatera- Java reached -1.2 °C. As oceanic response to easterly wind anomalies along the equator, the observed zonal currents in the central and eastern equatorial Indian Ocean also showed prominent westward currents during the peak phase of the 2011 IOD event.