Microphysical Features During Rainfall Events in Bandung, West Java. Case Study: Weather Modification Technology in Citarum Basin, November 2021

Supporting the Weather Modification Technology operating over Citarum Basin in October–November 2021, several rainfall observation instruments were installed around Bandung Area. Those instruments include X-band dual-polarization weather radar, Laser Precipitation Monitor (LPM) or laser disdrometer, and Automatic Weather Station (AWS). This study explored the rainfall characteristics around the Bandung area during November 2021. AWS was used to show accumulated rainfall amount; weather radar data was used to explore and analyze precipitation development mechanism both in temporal and spatial resolution; meanwhile, an LPM disdrometer was used to measure microphysics parameters of the rainfall such as the raindrop size and the number of raindrops, the velocity of the raindrops, reflectivity, and rainfall intensity. The temporal resolution of the weather radar was 5 min, the AWS was 5 min, and the LPM was 1 min. From the AWS data, the rainfall amount in November 2021 was recorded at around 491.5 mm, and the rainfall events mainly occurred in the afternoon until nighttime (11.00–22.00 LT). Data analysis from LPM (rainfall intensity, drop size, and number) showed that rainfall events from the convective or stratiform clouds over the Bandung area occurred in November 2021. Finally, cloud and precipitation development analyzed by weather radar data showed precipitation/cloud movement mainly propagated from North–North East to South, South–West, and West areas. Precipitation development from the south area also propagated to the Northern Bandung. Exploring and analyzing the microphysics characteristics of precipitation would help to determine the most suitable areas for cloud seeding activity.