Regional Precipitation Anomalies Associated with the El Niño–Southern Oscillation, Brazil
Keywords:
ENSO, rainfall, long-term precipitation dataAbstract
This study analyses the El Niño-Southern Oscillation (ENSO) climate variability for  better understanding of the processes leading to alternated anomalous precipitation regimes in Jeriquara city (São Paulo state, Brazil) (20º18’’40S;47º35’’21W). The monthly and annual pluviometric data over 1970 to 2000. The results clearly indicated the tendency that the mean monthly precipitation in El Niño phase is higher as compared to the neutral and La Niña phases. Comparing the average total rainfall for the period with the occurrence of ENSO phenomena it can be observed that in general, positives anomalies (excessive rainfall) have occurred during El Niño events and negative anomalies (deficits of precipitation) showing that ENSO (El Nino and La Nina) phenomenon are partially responsible for the precipitation regime over the region During El Niño events, precipitation averages was above normal, while La Niña events lead to precipitation amounts which average was below normal. This pattern of seasonal variation of precipitation in association with ENSO could help water resource managers of the state in decision making.
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