| Abstrak/Abstract |
El Niño-Southern Oscillation (ENSO) is a global climate phenomenon recognised for its effects on regional climates and irregularities in climate variability worldwide. In this article, the impact of ENSO on rainfall anomalies in Central Java, Indonesia, was investigated from 1990 to 2019. The Oceanic Niño Index (ONI) was used to determine the ENSO phase, and rainfall estimates by the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) and rainfall records from several meteorological stations were used to identify the anomalies. The anomalies were explained in relation to the degree of strength of El Niño and La Niña events. The results showed that strong El Niño caused a decrease in annual rainfall intensities to the entire region, particularly in the mountainous area in the western part (Pemalang, Pekalongan, Purbalingga, Banjarnegara) and northeast part (Jepara, Kudus, Pati). The decrease in annual rainfall reached 1300 mm during strong El Niño. The moderate and weak El Niño also affect those areas, while the mountainous area in the west part and southwest part is not affected. The moderate and weak El Niño contributes to decreasing rainfall of up to 900 mm, with notable differences in the affected area. Strong La Niña affects the entire study area, with increasing annual rainfall up to 1700 mm, while moderate and weak La Niña less affects the region, and a notable difference was not identified. The result also shows that the spatial distribution of this decrease in rainfall is across the northern regions and became increasingly less towards the south during strong El Niño. Conversely, strong La Niña increased the rainfall intensity, starting from the south and weakening northward. The effect enhanced significantly with La Niña’s strength, especially on the southern coast of the study area. |
