C.A. Skeie, N. Østgaard, A. Mezentsev, T. Neubert, V. Reglero, O. Chanrion, M. Marisaldi, P. Kochkin, N. Lehtinen, D. Sarria, C. Maiorana, A. Lindanger, I. B. Engeland, The relationship between the TGF durations and the relative onset times of the TGFs and main optical pulse, AGU Fall Meeting, San Francisco, 9-13 December, 2019