Pengaruh Super Indian Ocean Dipole (IOD) terhadap Anomali Curah Hujan Indonesia Tahun 2019
Abstract
Indian Ocean Dipole (IOD) merupakan fenomena interaksi lautan dan
atmosfer yang terjadi di kawasan Samudera Hindia. IOD memiliki keterkaitan
dengan variasi iklim Indonesia, terutama variabilitas curah hujan. IOD cenderung
terjadi bersamaan dengan El-Nino Southern Oscilation (ENSO), Namun hasil
penelitian lainnya menemukan bahwa IOD dapat terjadi tanpa diiringi oleh ENSO.
Salah satu IOD yang tidak diiringi ENSO adalah IOD (+) 2019. IOD juga memiliki
keterkaitan dengan zona konvergensi (ITCZ). Penelitian bertujuan untuk
mempelajari kondisi curah hujan Indonesia saat terjadinya IOD (+) 2019 serta
keterkaitannya dengan sirkulasi atmosfer dengan menganalisis data-data curah
hujan dan atmosfer. Penelitian ini meliputi tahapan analisis klimatologis curah
hujan Indonesia, penentuan indeks IOD, analisis korelasi indeks IOD dengan curah
hujan Indonesia, analisis anomali curah hujan dan suhu permukaan laut Indonesia
tahun 2019, serta analisis klimatologis dan anomali zona konvergensi wilayah
Indonesia tahun 2019. Hasil penelitian menunjukan bahwa IOD (+) 2019
menyebabkan penurunan curah hujan Indonesia, terutama saat memasuki periode
bulan kering (Juli-September). IOD (+) 2019 juga menyebabkan terjadinya
kontraksi/penyusutan ITCZ, sehingga menyebabkan terjadi penurunan curah hujan,
terutama di Indonesia bagian Barat. Indian Ocean Dipole (IOD) is a phenomenon of ocean and atmosphere
interaction that occurs in the Indian Ocean region. IOD has a relationship with
Indonesia's climate variations, especially rainfall variability. IOD tends to occur
simultaneously with the El-Nino Southern Oscilation (ENSO), but other studies
have found that IOD can occur without ENSO. One of the IODs that is not
accompanied by ENSO is IOD (+) 2019. IOD also has a relationship with the
convergence zone (ITCZ). This study aims to study the conditions of rainfall in
Indonesia during the IOD (+) 2019 and its relationship to atmospheric circulation
by analyzing rainfall and atmospheric data. This research includes the stages of
climatological analysis of Indonesian rainfall, determination of the IOD index,
correlation analysis of the IOD index with Indonesian rainfall, anomaly analysis of
rainfall and sea surface temperature in Indonesia in 2019, as well as climatological
analysis and anomaly of the convergence zone of the Indonesian region in 2019.
The results show that IOD (+) 2019 causes a decrease in Indonesia's rainfall,
especially when entering the dry month period (July-September). IOD (+) 2019 also
caused a contraction/shrinkage of the ITCZ, causing a decrease in rainfall,
especially in western Indonesia.