2016 Volume 12 Pages 37-41
El Niño Southern Oscillation (ENSO) influences on rainfall extremes around Sulawesi and the Maluku Islands in the eastern Indonesian Maritime Continent were investigated focusing on spatial and seasonal aspects using daily rainfall data at 23 stations during 1972-2012. The results show that interannual variations in rainfall extremes were strongly correlated with the ENSO phases. Wetter (drier) conditions were associated with La Niña (El Niño) events, in terms of total precipitation, rainy days, and consecutive dry days at more than 90% of the stations. Dry days tend to increase more than 2 months in the El Niño than La Niña years causing severe droughts in the region. Frequency and number of stations of heavy rainfalls increased (decreased) during La Niña (El Niño) events, whereas ENSO influences were weak (strong) on severest (moderately intense) rainfall events. ENSO influences on rainfall amount and number of rainy days vary spatially and seasonally. They were predominant during July–November but less during December–February. Heavy rainfall frequency was significantly higher during La Niña than El Niño years in transitional seasons.
