Climate extremes over the maritime continent and their associations with Madden-Jullian Oscillation

Abstract

Madden-Jullian Oscillation (MJO) has a strong influence towards rainfall over The Maritime Continent (MC). Due to possible impacts towards extreme precipitation in this area, a study is required to determine the influence of those processes. This research aims to investigate the influence of MJO on extreme precipitations over Indonesian Maritime Continent. To investigate the influence of those three processes, satellite precipitation data from The Tropical Rainfall Measuring Mission (TRMM) 3B42 product and Real time multivariate MJO (RMM) Index are used. Several extreme indices are calculated to identify magnitude of the extremes by calculating the area coverage of a specific precipitation threshold in each climate zone. Principal component analysis (PCA) is implemented to these indices to reduce large number of data into smaller number of information. Correlation analysis is implemented to the PCA and then matched to the MJO index to identify degree of influence of each process. Comparison of winds and mean sea level pressure data during each phenomenon is conducted to identify the key elements that control the generation of extreme precipitation. The result indicates extreme rain events in Indonesia could be triggered by the MJO, particularly during phase 4-6.