Effects of El Niño–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) on Extreme Temperatures in Indonesia

Abstract

As a tropical country, Indonesia also experiences extreme temperature changes due to world climate change. This research evaluates changes in extreme temperature trends in Indonesia over the last 45 years (1979-2023). The evaluation of this temperature trend uses the Mann-Kendal test and the Sequential Mann-Kendal test, which uses maximum and minimum temperature data from the Climate Prediction Center (CPC). We also apply a partial correlation of each index to the Niño3.4 index and Dipole Mode Index (DMI) to determine the dominant influence of these two indices on each extreme temperature index. The results showed an increase in monthly maximum of daily maximum temperature (TXx), monthly minimum of daily maximum temperature (TXn), monthly minimum of daily minimum temperature (TNn), and DTR of 0.08 °C/year, 0.18 °C/year, 0.09 °C/year, and 0.19°C/year, respectively. Apart from that, monthly minimum of daily minimum temperature (TNx) decreased by 0.16 °C/year. Minimum daytime and nighttime temperatures increase faster than maximum temperatures. Spatially, the increasing trend can be seen in almost all regions, showing an increasing trend in extreme temperatures, except for TNx. Partial correlation analysis shows that El Niño–Southern Oscillation (ENSO) has more influence on extreme temperatures than the Indian Ocean Dipole (IOD)