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Southern Oscillation Index (SOI)

The SOI index is the normalized difference in pressure between Darwin, Australia and Tahiti. It is associated with El Niño and La Niña phases of ENSO.

Data source and calculation

The index is calculated by NOAA/CPC (last update 15-SEP-2016). view details of calculation »

The standard deviation of the index over the period 1948-2005 is indicated on the plot. get series (netcdf 12kB) »