Intensity of the IOD is represented by anomalous SST gradient between the western equatorial Indian Ocean (50oE-70oE and 10oS-10oN) and the south eastern equatorial Indian Ocean (90oE-110oE and 10oS-0oN). This gradient is named as Dipole Mode Index (DMI). When the DMI is positive then, the phenomenon is refereed as the positive IOD and when it is negative, it is refereed as negative IOD. This dataset can be downloaded in a netcdf format here. Since, IOD is a coupled ocean-atmosphere phenomenon it can also be represented by any other atmospheric (pressure, olr) or oceanographic (sea surface height) as well. DMI derived from OLR anomalies can be downloaded from here.

SST DMI dataset (from 1958 to 1999, as in Nature paper of Saji et al., 1999)

SST DMI dataset (Seasonal)

SST DMI dataset (Yearly time series averaged from June to November)

SST DMI dataset (from 1871 to 1997) derived from GISST dataset

SST DMI dataset (from 1856 to Present) derived from Kaplan (1998)

SST DMI dataset (from 1982 to Present) derived from NOAA OI SST data (base period 1970-2005)

IOC UNESCO website link for all important indices

OLR DMI dataset

SLP DMI dataset

SST in the two representative boxes of the Indian Ocean Dipole

IOD home

Webpage maintained by Suryachandra A. Rao