The Utilization of Rapid Scan Observation Data through Rapid Development Cumulus Area Index to Estimate Updraft

Abstract

Rapid Scan Observation (RSO) of Himawari-8 data is used to generate Rapid Development Cumulus Area (RDCA) index ranging from 0.1 to 0.9 by adapting logistic regression model. RDCA indicates the developing process of cumulus clouds that are potentially expected to evolve into thunderstorm within one hour in around 10 km 2 area. As the RDCA index represents cloud development without updraft information, we try to prove the RDCA index can reflect updraft information by comparing the time series of RDCA index with differential reflectivity parameter (ZDR) and vertical wind velocity estimation obtained by multi Doppler analysis. Based on two cases, we found a good temporal correlation between RDCA index time series and ZDR for two cases, and only one case has a good temporal correlation between RDCA index and vertical wind velocity estimation.