The sequence of events in a lightning stroke: terrestrial gamma ray flash, radio signal and optical lightning.

Tuesday, 15 December 2015: 09:30
3001 (Moscone West)
Nikolai Ostgaard1, Thomas Gjesteland1,2, Hugh J Christian Jr3, Kjetil Albrechtsen1, Brant E Carlson4, Andrew Collier5, Steve Cummer6 and Gaopeng Lu7, (1)University of Bergen, Birkeland Centre for Space Science, Bergen, Norway, (2)University of Agder, Grimstad, Norway, (3)University of Alabama in Huntsville, Huntsville, AL, United States, (4)Carthage College, Kenosha, WI, United States, (5)University of KwaZulu-Natal, KwaZulu, South Africa, (6)Duke University, Electrical and Computer Engineering Department, Duke, NC, United States, (7)Institute of Atmospheric Physics, CAS, Beijing, China
Two observations of simultaneous terrestrial gamma ray flashes (RHESSI) and optical lightning (LIS) from space and radio signals on ground (WWLLN and Duke) will be presented. Both events indicate that radio waves come from the TGF itself, while the optical signal is slightly delayed. These observations are consistent with the TGF being produced in one of the last leader steps in an IC+ lightning stroke, and that the optical signal is produced when the leader reaches the positive charge layer.We will also present results showing that there are even more weak TGFs, than currently reported, in the RHESSI data set.