[M-IS23] Fusion of volcanology and meteorology

[MIS23-04] Simultaneous observation of cumulonimbus by polarimetric radar and ship radar

*Koji Sassa¹, Akane Higashikawa² (1.Natural Science Cluster, Kochi University, 2.Dept.of Science and Technology, Kochi University)

Keywords:polarimetric radar, ship radar, cumulonimbus, observation

Recently, hydrometeor classification is made to understand the inner structure of cumulonimbus. Moreover, the moving velocity, horizontal divergence and vortical structure in the cumulonimbus are also captured from the Doppler velocity data of the radar. However, dual Doppler analysis with more than two radars is needed to grasp the three-dimensional detailed flow structure of the cumulonimbus.
Ship radar has high range resolution of 10 m in range bin and its scan rate is 22 rpm. When we make RHI scan of the cumulonimbus, we can get the detailed flow field in the vertical cross section, tracking the echo pattern of reflectivity.
The present observational study aims to understand the detailed structure of cumulonimbus. We made simultaneous observation of thunderstorm in summer season by the polarimetric radar and ship radar.
Initial results show that raindrop is classified in the lower layer of the thunderstorm and graupel is observed upper layer above the melting layer. The updraft and downdraft are also observed in the thunderstorm.