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The properties of large amplitude whistler mode waves in the magnetosphere: Propagation and relationship with geomagnetic activity
Ist Teil von
Geophysical research letters, 2011-09, Vol.38 (17), p.n/a
Ort / Verlag
Washington, DC: Blackwell Publishing Ltd
Erscheinungsjahr
2011
Quelle
Access via Wiley Online Library
Beschreibungen/Notizen
We present results of a study of the characteristics of very large amplitude whistler mode waves inside the terrestrial magnetosphere at radial distances of less than 15 RE using waveform capture data from the Wind spacecraft. We observed 247 whistler mode waves with at least one electric field component (105/247 had ≥80 mV/m peak‐to‐peak amplitudes) and 66 whistler mode waves with at least one search coil magnetic field component (38/66 had ≥0.8 nT peak‐to‐peak amplitudes). Wave vectors determined from events with three magnetic field components indicate that 30/46 propagate within 20° of the ambient magnetic field, though some are more oblique (up to ∼50°). No relationship was observed between wave normal angle and GSM latitude. 162/247 of the large amplitude whistler mode waves were observed during magnetically active periods (AE > 200 nT). 217 out of 247 total whistler mode waves examined were observed inside the radiation belts. We present a waveform capture with the largest whistler wave magnetic field amplitude (≳8 nT peak‐to‐peak) ever reported in the radiation belts. The estimated Poynting flux magnitude associated with this wave is ≳300 μW/m2, roughly four orders of magnitude above estimates from previous satellite measurements. Such large Poynting flux values are consistent with rapid energization of electrons.
Key Points
Large amplitude whistler waves are not rare in the radiation belts
They can have >8 nT and/or >200 mV/m amplitudes and >300 μW/m2
They are capable of energizing particles on very short time scales