ABSTRACT
Indian Oceaon is influenced by the monsoon cycle. Monsoon cycle that occurs in the Indian Ocean influences the current patterns. Since a very strong westerlies occurs in The Tropical Convergence Zone TCZ at the equator, wyrtji jet is formed in the 40o 80o W lndian Ocean on a transitional season. Its branchs are possibly formed when the western coast of Sumatra which eventually creates South java Current SJC. SJC flows southeastward during December until April and northwestward during June until October, when it is associated with coastal upwelling. SJC develop upwelling on a seasonal basis.