A ground level gamma‐ray burst observed in association with rocket‐triggered lightning

Abstract

We report the observation of an intense gamma‐ray burst observed on the ground at sea level, produced in association with the initial‐stage of rocket‐triggered lightning at the International Center for Lightning Research and Testing at Camp Blanding, FL. The burst was observed simultaneously on three NaI(Tl)/photomultiplier tube detectors that were located 650 m from the triggered lightning channel with gamma‐ray energies extending up to more than 10 MeV. The burst consisted of 227 individual gamma‐rays that arrived over a 300 μs time period in coincidence with an 11 kA current pulse. The burst of gamma‐rays had very different characteristics from the x‐ray emission frequently seen in association with the dart leader/return stroke sequences of triggered lightning and may represent a new kind of event, likely originating from cloud processes thousands of meters overhead.

Localization of the source of terrestrial neutron bursts detected in thunderstorm atmosphere

“…This is the case because the hard g rays were observed to be associated with tropospheric sources [cf., e.g., Eack et al, 1996;Chubenko et al, 2000;Torii et al, 2002;Dwyer et al, 2004;Tsuchiya et al, 2007Tsuchiya et al, , 2009, and references therein].…”

Origin and context of C. T. R. Wilson's ideas on electron runaway in thunderclouds

“…Today it is known that energetic gamma radiation is produced in abundance by thunderclouds [Parks et al, 1981;Parks, 1985, 1992;Eack et al, 1996aEack et al, , 1996bEack et al, 2000;Moore et al, 2001;Dwyer et al, 2004aDwyer et al, , 2004bDwyer et al, , 2005Smith et al, 2005], contrary to Wilson's expectation. It is also recognized that the substantially greater ranges in air of gamma rays (in comparison with b rays of the same energy) are needed for energetic particles to escape the dense atmosphere to be detected in space [Williams et al, 2006].…”

“…These details are obviously important in understanding apparent discrepancies between findings by Schonland, Viljoen and Halliday, and the more recent results beneath thunderclouds [Moore et al, 2001;Dwyer et al, 2004aDwyer et al, , 2004bDwyer et al, , 2005.…”

“…Dwyer et al [2005] found similar results in Florida. Dwyer et al [2004aDwyer et al [ , 2004b have also detected X-radiation is association with rocket-triggered lightning at Camp Blanding, Florida.…”

“…[66] It is ironic that the location in the immediate thunderstorm environment, below cloud base where energetic particles are best documented today [Moore et al, 2001;Dwyer et al, 2004aDwyer et al, , 2004bDwyer et al, , 2005 is not the location emphasized for prevalence by Wilson's [1956] final reflection on the problem. The essentially negative results of Schonland [1930] in his initial search beneath the cloud undoubtedly played a role here.…”