THE IMPACT OF INDIAN OCEAN DIPOLE ON MADDEN JULIAN OSCILLATION PROPAGATION IN MARITIME CONTINENT

• Main Author: Gifari Kertabudi, Faridl
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46463
• Institution: Institut Teknologi Bandung

Madden Julian Oscillation is a large-scale circulation at the equator and centered in the Indian Ocean characterized by the growth of Super Cloud Cluster (SCC). MJO requires certain climate condition to propagate eastward. Maritime Continent climate is affected by the Indian Ocean Dipole (IOD) phenomenon. There are two types of IOD phases, namely positive Dipole Mode and negative Dipole Mode. According to Marchant et al. (2006), both phase of IOD give different influences on climate condition in the area around the East Indian Ocean and the Maritime Continent. In this study, Maritime Continent climate conditions during IOD is analyzed using ERA Interim data which is composited based on the IOD phase. Then the IOD impact on MJO is analyzed using zonal wind data and Outgoing Longwave Radiation (OLR) which are filtered using the bandpass filter method for a period of 20 - 100 days. MJO propagation analysis is performed using the Hovmöller diagram. To analyze the strength of the MJO signal on the Maritime Continent, a spectral analysis is performed. From the results, during negative Dipole Mode, MJO becomes stronger as it propagates eastward. This is due to higher humidity conditions and stronger westerly winds than normal so that MJO could propagate on the Maritime Continent. During positive Dipole Mode, MJO experiences obstacles when it propagates eastward. This is due to lower humidity conditions and stronger easterly winds than normal so that MJO propagation is restrained when entering Maritime Continent and then dissipated. Negative OLR area which represents MJO is getting smaller during its propagation towards the Maritime Continent. The MJO signal in the Maritime Continent is weaker based on the results of spectral analysis.