JpGU – AGU Joint meeting: N. Østgaard, S. Cummer, A. Mezentsev, T. Neubert, V. Reglero, O. Chanrion, M. Marisaldi, P. Kochkin, N. Lehtinen, D. Sarria, C. Maiorana, C. Skeie, A. Lindanger, Y. Pu, F. Christiansen, C.Eyles, K. Ullaland, G. Genov, One TGF and two elves produced by the same thunderstorm system, Chiba, Japan, 24-28 May, 2020 (Invited talk)