In this study, the Oceanic Nino Index (ONI) is used indicators.
The ONI is an index calculated from the sea surface temperature (SST). The ONI values are calculated from the Niño 3 area during the region 5°North to5°South ,150°West-90°West and the Niño 3.4 area during 5°N to 5°S, and 170°W to 120°W. This value to NOAA has used as an index to predict the occurrence of ENSO phenomenon and evaluate the strength of the spectacle.