Calculating emission and atmospheric transport of neutrons, protons and positrons from thunderstorm

Abstract:

Thunderstorms are by now known to emit flashes of gamma-rays, electrons and positrons, and theory predicts that they can also generate neutrons and protons with energies of up to tens of MeV [Babich, 2007, Geomag. and Aero., vol 47, pp. 664-670; Koehn and Ebert, 2014, Submitted to JGR]. But how far would neutrons and protons propagate and where could they be measured? To calculate the energy losses and the absorption of hadrons in air, we have reviewed the latest literature on cross sections for hadron scattering at air molecules and implemented them into a three dimensional Monte Carlo code. Then we calculate two type of data: 1. the energy dependent absorption length of hadrons and leptons in a given column density of air in the absence of electric fields, providing absorption data for arbitrary orientations and altitudes of air columns, and 2. specific generation, propagation and absorption data for generic leader events in thunderstorms, both directed upwards in the cloud and propagating downwards towards the ground.