Terrestrial gamma ray flashes observed aboard the Compton Gamma Ray Observatory/Burst and Transient Source Experiment and ELF/VLF radio atmospherics

During its 9-year lifetime in orbit, the Burst and Transient Source Experiment (BATSE) detector, aboard the Compton Gamma Ray Observatory (CGRO) spacecraft, observed a total of 76 terrestrial gamma ray flashes (TGFs). Of these, simultaneous broadband ELF/VLF data from Palmer Station, Antarctica, were found to be available for six new TGF cases in addition to two previously reported cases (Inan et al., 1996). Analysis of temporal and directional association between radio atmospherics and TGFs reveals solid evidence of an associated radio atmospheric in three of the six events. In one of the three cases with associated radio atmospherics, three consecutive TGFs are apparently linked to three consecutive radio atmospherics. A fourth case exhibits possible evidence of geomagnetically conjugate source lightning. Statistical analyses indicate that when TGFs occur in association with a lightning discharge, they occur ~1-3 ms after the causative lightning event.