In this study, the Oceanic Nino Index (ONI) is used indicators.
The ONI is an index calculated from the sea surface temperature (SST). By ONI values are calculated from the area called the Niño 3.0 index during the region 5°North to5°South ,150°West-90°West and the Niño 3.4 region during 5°N to 5°S, and 170°W to 120°W. And this value to NOAA has used as an index to predict the occurrence of ENSO phenomenon and evaluate the strength of the spectacle.