Premium
Van Allen Probe observations of periodic rising frequencies of the fast magnetosonic mode
Author(s) -
Boardsen S. A.,
Hospodarsky G. B.,
Kletzing C. A.,
Pfaff R. F.,
Kurth W. S.,
Wygant J. R.,
MacDonald E. A.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl062020
Subject(s) - plasmasphere , spacecraft , van allen probes , physics , plasma , magnetic field , mode (computer interface) , computational physics , proton , low frequency , astrophysics , magnetosphere , van allen radiation belt , astronomy , quantum mechanics , computer science , operating system
Near simultaneous periodic dispersive features of fast magnetosonic mode emissions are observed by both Van Allen Probes spacecraft while separated in magnetic local time by ~5 h: Probe A at 15 and Probe B at 9–11 h. Both spacecraft see similar frequency features, characterized by a periodic repetition at ~180 s. Each repetition is characterized by a rising frequency. Since no modulation is observed in the proton shell distribution, the plasma density, or in the background magnetic field at either spacecraft we conclude that these waves are not generated near the spacecraft but external to both spacecraft locations. Probe A while outside the plasmapause sees the start of each repetition ~40 s before probe B while deep inside the plasmasphere. We can qualitatively reproduce the dispersive features but not the quantitative details. The cause for this phenomena remains to be identified.