Madden Julian Oscillation Influence on Diurnal Variation of Rainfall in Mentawai Islands Indonesia from IMERG Observations

• Published in: Journal of physics. Conference series 2024-10, Vol.2866 (1), p.12069
• Main Authors: Erajalita, A, Marzuki, M, Vonnisa, M, Ramadhan, R, Yusnaini, H, Sari, A Y
• Format: Article
• Language: English
• Subjects: Diurnal variations; Madden-Julian oscillation; Rainfall; Satellite observation
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/2866/1/012069

Mentawai is a small island located in the Indian Ocean, so its rainfall pattern tends to be different from the larger islands in Indonesian region. Various scales of factors influence this, one of which is Madden Julian Oscillation (MJO). The aim of this study is to determine effect of MJO in Mentawai Islands on the diurnal variation of rainfall. Rainfall data was collected from 2000-2022 from Integrated Multi-SatellitE Retrievals for GPM (IMERG). Diurnal variations were observed in the accumulation (PA), frequency (PF), and intensity (PI) of rainfall and MJO was classified into active phase (2, 3, 4, and 5) and inactive phase (1, 6, 7, and 8) during the seasonal period (DJF-MAM-JJA-SON). Diurnal peak times in PA, PF, and PI occur later when MJO is active than when MJO is inactive, especially in JJA and SON periods in Mentawai Islands and Mentawai Strait. When MJO is active, average PA and PF are higher than when MJO is inactive. The average of PI is higher around the ocean during active and inactive phases of MJO. The number of short-duration rainfall events occurred over the land, while long-duration rainfall occurred over the ocean.