THE EVOLUTION OF SURFACE AND SUBSURFACE TEMPERATURES IN WEST SUMATRA AND SOUTH JAVA SEAS DURING INDIAN OCEAN DIPOLE (IOD) EVENTS IN 2010 – 2014

• Main Author: R Khairun Nisa', A
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/51886
• Institution: Institut Teknologi Bandung

This study aims to study the evolution of sea surface temperature anomalies (SST) and in the subsurface layers that occur in the West Sumatra and South Java seas in studying the formation mechanism of the Indian Ocean Dipole (IOD). Surface temperature data were used to a depth of 300 m from the HYCOM output in 2010-2014 to analyze the evolution of temperature anomalies on the surface and subsurface layer during negative IOD (n-IOD) event in 2010 and positive IOD (p-IOD) event in 2012. The data were processed and then presented using a cross-section plot and Hovmöller diagrams. It has shown that in the negative IOD 2010 that happen in August-October, a positive temperature anomaly in the subsurface layer was started four months earlier than the surface layer and ended six months after the IOD event. In contrast to positive IOD 2012 that happen in August-September, a negative temperature anomaly formed in the surface layer seven months earlier, and then move to the deeper layer coincide with the onset of the positive IOD event. The negative anomaly in both layers was simultaneously over two months after the positive IOD event over. The La-Niña phase that coincides with the positive or negative IOD event, influences the process of forming temperature anomalies in the subsurface layer, which in this case supports (inhibits) the formation of positive (negative) temperature anomalies in negative (positive) IOD event. The temperature anomaly in the subsurface layer can be an alternative indicator in identifying and predicting IOD events.