Precipitating electron events in October 2003 as observed in the polar atmosphere

Balloon cosmic ray measurements at polar latitudes (Apatity station, geomagnetic vertical cutoff rigidity Rc = 0.6 GV, invariant latitude Λ = 65°, and Mirny observatory, Antarctica, Rc = 0.03 GV, Λ = −77°) in October 2003 were analysed. During this period, several energetic electron precipitation events were recorded via the bremsstrahlung generated by the electrons in the atmosphere. In order to determine the flux and the energy spectrum of precipitating electrons on the atmospheric boundary the simulation of electron and X-ray transport in the atmosphere was performed using the Geant4 Monte Carlo code. By comparing the results of balloon measurements with the simulation results, we deduced the precipitating electron flux during the 22 October 2003 event as Je (E) = 7.7 × 106 exp (−E/12 keV), cm−2 s−1 keV−1.