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.