Impact of El Niño and El Niño Modoki Events on Indonesian Rainfall
On an interannual time-scale, the Indonesian climate is strongly influenced by the dynamics of Indo-Pacific climate modes. This study aims to investigate the possible impact of different types of El Niño events, namely, typical El Niño and El Niño Modoki, on Indonesian rainfall variability. Season...
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doaj-79b32f9ef5ef454aa7fdbe5b2252be612020-11-25T03:28:20ZengUniversitas IndonesiaMakara Journal of Science2339-19952356-08512019-12-0123421722210.7454/mss.v23i4.11517Impact of El Niño and El Niño Modoki Events on Indonesian RainfallIskhaq Iskandar0Deni Okta Lestrai 1Muhammad Nur 2Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Sriwijaya, PalembangGraduate School of Environmental Science, Universitas Sriwijaya, Palembang 30139, Indonesia Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Sriwijaya, Palembang 30662, Indonesia On an interannual time-scale, the Indonesian climate is strongly influenced by the dynamics of Indo-Pacific climate modes. This study aims to investigate the possible impact of different types of El Niño events, namely, typical El Niño and El Niño Modoki, on Indonesian rainfall variability. Seasonal composite analysis was used to evaluate the magnitude and significance level of the influence of El Niño on the rainfall variability over the Indonesian region. Typical El Niño (hereafter El Niño) has a stronger influence on Indonesian rainfall than the El Niño Modoki during boreal autumn in September, October, and November when the events almost reach their peak. Cold sea surface temperature (SST) anomalies were observed in the Indonesian sea and in the western Pacific during El Niño years, while cold SST anomalies covered only the eastern Indonesian sea during El Niño Modoki years. Strong cold SST anomalies during El Niño years led to stronger low-level wind divergence over the Maritime Continent compared with that during El Niño Modoki years. In addition, the Walker circulation during El Niño years revealed a stronger downward motion over the Maritime Continent than that observed during El Niño Modoki years. This stronger downward motion (low-level wind divergence) during El Niño years reduced lower atmospheric water vapor and suppressed atmospheric convection over the Maritime Continent, leading to a significant decrease in rainfall. Similar situations were also observed during El Niño Modoki years but with a much weaker amplitude. https://scholarhub.ui.ac.id/cgi/viewcontent.cgi?article=1150&context=scienceel niñoel niño modokimaritime continentrainfallsea surface temperature |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Iskhaq Iskandar Deni Okta Lestrai Muhammad Nur |
spellingShingle |
Iskhaq Iskandar Deni Okta Lestrai Muhammad Nur Impact of El Niño and El Niño Modoki Events on Indonesian Rainfall Makara Journal of Science el niño el niño modoki maritime continent rainfall sea surface temperature |
author_facet |
Iskhaq Iskandar Deni Okta Lestrai Muhammad Nur |
author_sort |
Iskhaq Iskandar |
title |
Impact of El Niño and El Niño Modoki Events on Indonesian Rainfall |
title_short |
Impact of El Niño and El Niño Modoki Events on Indonesian Rainfall |
title_full |
Impact of El Niño and El Niño Modoki Events on Indonesian Rainfall |
title_fullStr |
Impact of El Niño and El Niño Modoki Events on Indonesian Rainfall |
title_full_unstemmed |
Impact of El Niño and El Niño Modoki Events on Indonesian Rainfall |
title_sort |
impact of el niño and el niño modoki events on indonesian rainfall |
publisher |
Universitas Indonesia |
series |
Makara Journal of Science |
issn |
2339-1995 2356-0851 |
publishDate |
2019-12-01 |
description |
On an interannual time-scale, the Indonesian climate is strongly influenced by the dynamics of Indo-Pacific climate
modes. This study aims to investigate the possible impact of different types of El Niño events, namely, typical El Niño
and El Niño Modoki, on Indonesian rainfall variability. Seasonal composite analysis was used to evaluate the
magnitude and significance level of the influence of El Niño on the rainfall variability over the Indonesian region.
Typical El Niño (hereafter El Niño) has a stronger influence on Indonesian rainfall than the El Niño Modoki during
boreal autumn in September, October, and November when the events almost reach their peak. Cold sea surface
temperature (SST) anomalies were observed in the Indonesian sea and in the western Pacific during El Niño years,
while cold SST anomalies covered only the eastern Indonesian sea during El Niño Modoki years. Strong cold SST
anomalies during El Niño years led to stronger low-level wind divergence over the Maritime Continent compared with
that during El Niño Modoki years. In addition, the Walker circulation during El Niño years revealed a stronger
downward motion over the Maritime Continent than that observed during El Niño Modoki years. This stronger
downward motion (low-level wind divergence) during El Niño years reduced lower atmospheric water vapor and
suppressed atmospheric convection over the Maritime Continent, leading to a significant decrease in rainfall. Similar
situations were also observed during El Niño Modoki years but with a much weaker amplitude.
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topic |
el niño el niño modoki maritime continent rainfall sea surface temperature |
url |
https://scholarhub.ui.ac.id/cgi/viewcontent.cgi?article=1150&context=science |
work_keys_str_mv |
AT iskhaqiskandar impactofelninoandelninomodokieventsonindonesianrainfall AT denioktalestrai impactofelninoandelninomodokieventsonindonesianrainfall AT muhammadnur impactofelninoandelninomodokieventsonindonesianrainfall |
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