Niño 3 and Nino3.4 are mean of
the SST averaged over the 5°N-5°S, 150°W-90°W
region and the 5°N-5°S, 150°W-90°W
region respectively , where a large variability of the SST
associated with ENSO takes place.
Since the early
1980s this region has been considered as a reference
for the strength of the ENSO episodes. Niño 3 index and Nino3.4 index used in this study was obtained from the website of
NOAA’s Climate Prediction Centre
(http://www.cpc.ncep.noaa.gov/data/indices/).
ENSO events, which occur every 2-7 years, are
associated with either high or low Niño 3 indices. A
warm El Niño phase is characterised by high
positive Niño 3 values as warmer temperatures
prevail throughout the tropics. Conversely, negative
Niño 3 values indicate La Niña events, when the
tropics experience lower than normal temperatures.
The National Climate Centre of BOM provided the
continuous district-averaged monthly rainfall data
from Australia’s 107 rain districts.