Variation in extreme rainfall in indonesia associated with four propagation types of madden-julian oscillation

¹ Faculty of Earth Science and Technology - Bandung Institute of Technology, Bandung, Indonesia
² Yuvai Semaring Class III Meteorological Station, Nunukan - Meteorology, Climatology, and Geophysics Agency, Indonesia

^* Corresponding author: whitemailnew@gmail.com

Abstract

The impact of the MJO on extreme daily rainfall (x_MJO ≥ x_c), namely the 95th extreme, is known by quantifying the difference in probability of extreme daily rainfall during the MJO versus NDJFMA (△P_MJO) events. MJO has four propagation characteristics. In this study, the differences in the 95th extreme probability is the impact of the characteristics of each type of MJO propagation which are different from each other. MJO identification is by using a band-pass filter frequency against the daily average Outgoing Longwave Radiation and certain criteria. MJO identified according to certain criteria from the band-pass filter will be grouped based on the similarity of propagation types using the k-mean clustering method. In addition, a regional probability matrix of the 95th extreme probability difference is created. The positive (negative) difference in daily rainfall and the probability of the 95th extreme follows the propagation of the active phase (inactive phases) of each MJO type. The regional probability of a positive 95th extreme probability difference or positive probability (negative probability) also has the same or follows the propagation of active phase (inactive phases) for each MJO type from west to east, just like the similarity of the pattern of bulk difference daily rainfall and 95th extreme probability.