On the Relationship between Western Maritime Continent Monsoon Rainfall and ENSO during Northern Winter

Abstract

Abstract Several studies have reported that Indonesian rainfall is poorly correlated with El Nino–Southern Oscillation (ENSO) events during the northern winter wet monsoon season. This work studies the relationship between the Nino-3 (5°S–5°N, 150°–90°W) sea surface temperature (SST) and the Maritime Continent monsoon rainfall during 1979–2002. The study indicates that the correlations are mostly negative except in the vicinity of Sumatra and Malay Peninsula (SMP, including the western sections of Java and Borneo), where the correlations range from zero to weakly positive. The monsoon rainfall during ENSO events is influenced by a pair of anomalous Walker cells and a low-level closed circulation centered near the Philippines. East of SMP, the rainfall is negatively correlated with Nino-3 SST. The anomalous low-level wind over the Indian Ocean west of SMP causes rainfall to also be correlated negatively with Nino-3 SST, but rainfall over SMP is sheltered from this effect because of the high mountains along...