[M-IS19] Atmospheric electricity and application of technology for reducing disaster risks

[MIS19-P03] Relationships between Surface Rainfall and Lightning in Liner Rainbands in Japan

*Hiroto Ouchi¹, Yasuhide Hobara^1,2,3, Hiroshi Kikuchi^1,2, Debrupa Mondal¹, Jeff Lapierre⁴ (1.Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 1828585, Japan, 2.Center for Space Science and Radio Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 1828585, Japan, 3.Research Center for Realizing Sustainable Societies, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 1828585, Japan,, 4.Earth Networks, Germantown, MD 20874, USA)

Keywords:Total lightning, Linear rainbands

Linear rainbands are weather phenomenon that bring long periods of heavy rainfall and cause serious damage such as river flooding and landslides. With the acceleration of global warming, the frequency of their occurrence is predicted to increase, and improving forecast accuracy is an issue. Additionally, it has been recently reported that there is a strong correlation between precipitation and lightning frequency in convection cells that bring heavy rainfall, and in particular, it has been reported that the lightning frequency of intracloud lightning (IC) precedes surface precipitation volume (PV) by about 5 to 10 minutes. (Mondal et al., 2021).
In this study, we focus on linear rainbands that cause severe heavy rain damage in Japan and investigate the relationship between precipitation and lightning activity. For comparison, we also analyzed non-linear rainbands. We used ground precipitation data from the X-band Precipitation Radar (XRAIN) observation network deployed by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and lightning discharge data from the Japanese Total Lightning Network (JTLN) deployed by the University of Electro-Communications. As a result, it was confirmed that Lightning Jump (LJ) in IC occur approximately 25 minutes before a significant increase in PV in linear rainbands. In addition, cross-correlation analysis considering the time lag between PV and IC frequency in linear rainbands showed a very high correlation coefficient. Furthermore, it was confirmed that linear rainbands produce more precipitation even when the frequency of lightning is lower compared to non-linear rainbands. These results suggest that the temporal variation of total lightning occurrence, especially IC frequency, may be effective for improving precipitation nowcasting in linear rainbands.