地理と自然災害のジャーナル
オープンアクセス

概要

Refinement of Precipitation Distribution in Southern Brazil under the Conditions of the Pacific Ocean Temperature Anomaly

Osvaldo Luiz Leal de Moraes1*, Jose Marengo Orsini2

The role of the Pacific Decadal Oscillation (PDO) and the El Niño-Southern Oscillation (ENSO) was investigated in relation to anomalous precipitation in Southern Brazil. A daily precipitation dataset was used, covering the period 1961 to 2016 from 106 monitoring stations. In addition, a direct comparison was made between El Niño plus positive PDO events and La Niña plus negative PDO events to discover any correlations between these phenomena in regional precipitation. Our results indicate that significant monthly favorable anomalous precipitation across the region occurred only during intense or extreme El Niño events, and PDO had no modulating effect regardless of its intensity. However, monthly negative precipitation anomalies at higher latitudes ranged from low to moderate during robust La Niña periods, suggesting some association with adverse PDO events.