The Impact of Madden - Julian Oscillation and Sea Surface Temperature Process Interaction on Rainfall Variability During Rainy Season: A Case Study in East Nusa Tenggara, Indonesia

Abstract

Most studies of the impact of sea surface temperature (SST) have explored rainfall in a part of Indonesia. This paper takes a different approach and explores the impact of air-sea coupling interaction between Madden-Julian Oscillation (MJO) and SST on rainfall variability in East Nusa Tenggara (NTT). This study uses daily rainfall observation from some of the NTT seasonal zone (ZOM) from 1991to 2016. Meanwhile, the gridded data of SST around NTT was obtained from Japan Meteorological Agency (JMA). For the amplitude of MJO, the data was downloaded from the Bureau of Meteorology (BOM)’s website. This study used a statistical approach of conditional probability and gamma correlation to identify the impact of MJO-SST coupling interaction on rainfall variability in NTT. The results of this study showed that during rainy seasons and MJO located in phase 5, they are still a high probability of rainfall appearing in most NTT regions, even though SST is in cooling condition. The evidence shows that the result provides insights into the adequacy of MJO caused high rainfall variability in almost NTT regions in all of SST condition.