5:15 PM - 6:30 PM
[AAS13-P11] Frequency distribution of raindrop size observed by an optical disdrometer during heavy rainfall in Tokyo
Keywords:Raindrop size, Frequency distribution, Rainfall intensity, Optical disdrometer
Currently, optical disdrometers (Thies Clima Laser Precipitation Monitor 5.4110, etc.) are installed at six sites in the Tokyo Metropolis and Sendai City. In this study, using the observation data in Tokyo from April to September in 2014, minutely rainfall intensity and the number of raindrops for each 22 class of raindrop size (sphere equivalent diameter) were examined. Contribution ratio of raindrop water for each class to the rainfall amount was calculated to investigate the temporal changes in heavy rainfall case on July 20, 2014. As a result, it was observed that an increase in contribution ratio of large size raindrops corresponds to an increase in rainfall intensity. The difference in frequency distribution due to the relative position within a convective system and the temporal changes in the other heavy rainfall cases will also be investigated.