Impacts of the Madden-Julian Oscillation on Widespread Heavy Rainfall Over the Western Region of the Maritime Continent: Sumatra

Abstract

The Precipitation Severity Index (PSI) is used to examine the occurrence of and mechanisms behind widespread persistent rainfall events in Sumatra. Analysis of cloud properties from Himawari-8 is combined with data from IMERG and ERA5 to explore new results about changes in cloud properties relating to heavy rainfall and intraseasonal variability. This study brings a fresh angle to the challenge of understanding the Madden-Julian Oscillation (MJO) modulation of cloud and precipitation over Sumatra by examining changes in the total cloud area and, more importantly, changes in the cold cloud tops that indicate the deepest convection. Although widespread cold clouds are likely regardless of MJO..