Katsiyannis, Athanassios ; Dominique, Marie ; Pierrard, Viviane ; Lopez Rosson, Graciela ; De Keyser, Johan ; Berghmans, David ; Kruglanski, Michel ; Dammasch, Ingolf E. ; De Donder, Erwin

Talk presented at 14th European Space Weather Week on 2017-11-28

Abstract: To better understand the radiation environment in low Earth orbit (LEO), the analysis of in-situ observations of a variety of particles, at different atmospheric heights, and in a wide range of energies, is needed. We present an analysis of energetic particles, indirectly detected by the Large Yield RAdiometer (LYRA) instrument on board ESA's Project for On-board Autonomy 2 (PROBA2) satellite as background signal. Combining Energetic Particle Telescope (EPT) observations with LYRA data for an overlapping period of time, we identified these particles as electrons with an energy range of 2 to 8 MeV. The observed events are strongly correlated to geo-magnetic activity and appear even during modest disturbances. They are also well confined geographically within the L=4-6 McIlwain zone, which makes it possible to identify their source. Although highly energetic particles are commonly perturbing data acquisition of space instruments, we show in this work that ultra-relativistic electrons with energies in the range of 2-8 MeV are detected only at high latitudes, while not present in the South Atlantic Anomaly region.

Keyword(s): ionosphere ; ultra-relativistic electrons ; low Earth orbit ; geostatic orbit ; LYRA ; PROBA2 ; VLF/ELF waves ; ECH ; waves -- EMIC waves -- microbursts -- monoenergetic electrons
Funding: 3PRODSIDCEXPLOIT/3PRODSIDCEXPLOIT/3PRODSIDCEXPLOIT