Unit:
Κατεύθυνση Αστροφυσική, Αστρονομία και Μηχανική (ΒΑΣΙΚΗ ΦΥΣΙΚΗ)Library of the School of Science
Supervisors info:
Ιωάννης Δαγκλής, Καθηγητής, Τμήμα Φυσικής ΕΚΠΑ
Απόστολος Μαστιχιάδης, Καθηγητής, Τμήμα Φυσικής ΕΚΠΑ
Γεώργιος Μπαλάσης, Διευθυντής Ερευνών, ΙΑΑΔΕΤ
Original Title:
Effect of Very Low Frequency (VLF) waves on the acceleration of electrons to relativistic energies
Translated title:
Effect of Very Low Frequency (VLF) waves on the acceleration of electrons to relativistic energies
Summary:
Local acceleration driven by whistler mode chorus waves is fundamentally important for the acceleration of seed electrons in the outer radiation belt to highly relativistic energies. Yet, this mechanism strongly depends on substorm activity and on the source population injected by the substorms into the inner magnetosphere. In this work we use Van Allen Probes (RBSP) data to investigate the relationship between source electrons, seed electrons and chorus waves during periods of increased substorm activity. To that end we calculate the electron phase space density (PSD) for five values of the first adiabatic invariant μ corresponding to source and seed electrons, during 28 events, out of which, 20 result in enhancement and 8 in depletion of relativistic electron PSD. Furthermore, we perform a superposed epoch analysis in order to compare the time evolution of chorus activity with PSD, defining a key time t0 as the start time of continuous substorm activity, as indicated by the decrease of AL index.
Main subject category:
Science
Keywords:
Magnetospheric substorms, electrons, seed, source, relativistic, electromagnetic very low frequency waves, phase space density, magnetosphere, flux, Van Allen radiation belts, chorus waves, ULF waves, Pc5, adiabatic invariants, solar wind
