[M-IS13] Dynamics of eruption cloud and cumulonimbus; modelling and observation

[MIS13-P05] Ash fall observation using 2D-Video Disdrometer (2)

*Eiichi Sato¹, Kosei Takishita², Masato Iguchi³ (1.Meteorological Research Institute, 2.Division of Earth and Planetary Sciences, Graduate School of Science, Kyoto University, 3.Sakurajima Volcano Research Center, Disaster Prevention Research Institute, Kyoto University)

Keywords:2D-Video Disdrometer, Sakurajima volcano, ash fall, dual-polarization/polarimetric radar

Meteorological Research Institute (MRI) is conducting ash fall observations at Sakurajima Volcano using two-dimensional video disdrometers (2DVDs). 2DVD is originally a ground-based instrument that observes precipitation particles, and it is possible to obtain the three-dimensional shape and falling velocity of each target particle. This instrument is used in meteorology to verify polarimetric (dual-polarization) radar and to observe precipitation particles on the ground, but in volcanology there are few observations. MRI is developing a technology for estimating the amount of volcanic ash inside the eruption plume using a polarimetric radar. In addition, 2DVD observations are being conducted to obtain the “ground truth” data.
Here, we describe the main previous researches and current issues. Suh et al. (2019) conducted an indoor ash fall experiment to discuss the characteristics of volcanic ash particle shape, falling velocity, and canting angle, however, it is necessary to investigate the characteristics of the actual ash fall. Kozono et al. (2019) is an example of ash fall observation by a disdrometer in the natural environment. However, since the disdrometer used in this paper cannot recognize the shape of particles, it is not suitable for verification of dual-pol radar data.
In this presentation, we will report the outline of the quality control method of ash fall observation data by 2DVD and the verification method of the amount of volcanic ash retrieved using a polarimetric radar.