We investigate 3D distribution of VHF lightning radiation sources observed on November 30, 2010. The detailed structure of the thundercloud was observed with the X-band radar. The horizontal distribution of the VHF sources was consistent with the area of radar echo. The vertical distribution of the VHF sources was 1-5 km in altitude, corresponding to the echo-top height (about 5 km) observed by RHI scan. In particular, 22% of the source was located at 2.5-3 km in altitude. The -10 degree C level retrieved from JMA-MANAL was 2.8 km at the same time. Hence, we estimate that the electric charges accumulated around the -10 degree C level of 2.8 km. The vertical distribution of the VHF sources is related to the atmospheric temperature level. Similar tendency is shown in the other cases (e.g., Dec. 3, 2010; Dec. 14, 2011; Dec. 17, 2011). These results support the numerical study on rimming electrification mechanism (Takahashi 1984) and activity diagram for winter lightning (Michimoto 1993; Nishihashi et al. 2011).
In this presentation, we will also show the spatial-temporal relationship between lightning activities and vortex evolutions in winter thunderstorms.