Yosafat Donni Haryanto^1,, Niken Astrid Septyar¹, Adji Syarifah Happy¹, Nelly Florida Riama²

Ocean current is defined as the movement of sea water masses due to the dynamic relationship between the atmosphere and the oceans. One of the weather phenomena in the atmosphere which can affect the conditions of the ocean’s dynamics is the Madden Julian Oscillation (MJO). MJO is a movement of convection areas propagating eastward from the Indian Ocean to the Pacific Ocean over a 40 – 50 days period. Previous studies have shown that MJO activity can affect various parameters such as wind direction and speed, sea surface temperature, and ocean current patterns in the area in which it passes. This study aimed to determine changes in the pattern of ocean currents in the waters of the Sunda Strait when MJO is in an active and inactive phases. The dates and activities of MJO were determined using Real-Time Multivarate MJO (RMM) Index of Series 1 and Series 2 (RMM1 and RMM2) data. This research was conducted by utilizing MIKE 21 numerical model to describe the ocean currents when the MJO is in an active or inactive phase in the waters of the Sunda Strait. Data of bathymetry, coastline, wind, surface pressure, and tides were needed to run the model. Based on the analysis of the study, it was found that MJO activity influenced on the changes of ocean current patterns in the Sunda Strait waters. In addition, there was a significant influence on changes in the direction of ocean currents which occurred every 12 hours. The average current velocity also increased ranging from 0.5 – 1 m/s when the MJO was in the active phase.

ocean current, MJO, Sunda Strait