ANALYSIS OF PRECIPITATION MICROSTRUCTURE CHARACTERISTIC DURING MADDEN JULIAN OSCILLATION (MJO) PERIOD USING MICRO RAIN RADAR (MRR) AND DISDROMETER IN SOUTH TANGERANG

• Main Author: Nurheliza, Dede
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/48667
• Institution: Institut Teknologi Bandung

Rain microstructure is an important aspect to understand the dynamics and microphysics character of the clouds. Rain microstructure is characterized by the distribution of size, shape and fall velocity of raindrop. Raindrop size distribution (DSD) explain the detail of microphysical process because it represents process of rain to the surface. One of the phenomena that influences the rain patterns in Indonesia is Madden Julian Oscillation (MJO). Therefore, observing rain microstructure with its relation to MJO can determine the differences of rainfall characteristic and microphysical processes during active and inactive MJO period. The data used in this study are micro rain radar (MRR), disdrometer and real-time multivariate (RMM) index data. The period/date selection of active MJO event performed using RMM index method that is more than 1 in phases 4 and 5 and otherwise for inactive MJO. Types of the rain are divided into convective and stratiform rain based on disdrometer data. Rain microstructure in this study focuses on DSD from micro rain radar and disdrometer data analysed with liquid water content profil, fall velocity, reflectivity and rain rate from MMR. In addition, there are parameters of DSD which is mass-weighted diameter (Dm) and total concentration (Nw) calculated using the moment and gamma distribution method. The result show that DSD and other parameters are greater during inactive MJO period. This means that process of collision-coalescence, evaporation and updraft is dominant during inactive MJO period.