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Dayside response of the magnetosphere to a small shock compression: Van Allen Probes, Magnetospheric MultiScale, and GOES‐13
Author(s) -
Cattell C.,
Breneman A.,
Colpitts C.,
Dombeck J.,
Thaller S.,
Tian S.,
Wygant J.,
Fennell J.,
Hudson M. K.,
Ergun Robert,
Russell C. T.,
Torbert Roy,
Lindqvist PerArne,
Burch J.
Publication year - 2017
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 - 10.1002/2017gl074895
Subject(s) - physics , magnetopause , magnetosphere , van allen probes , shock (circulatory) , interplanetary spaceflight , geophysics , magnetohydrodynamics , van allen radiation belt , computational physics , shock wave , mechanics , magnetic field , astrophysics , solar wind , quantum mechanics , medicine
Observations from Magnetospheric MultiScale (~8 Re ) and Van Allen Probes (~5 and 4 Re ) show that the initial dayside response to a small interplanetary shock is a double‐peaked dawnward electric field, which is distinctly different from the usual bipolar (dawnward and then duskward) signature reported for large shocks. The associated E × B flow is radially inward. The shock compressed the magnetopause to inside 8 Re , as observed by Magnetospheric MultiScale (MMS), with a speed that is comparable to the E × B flow. The magnetopause speed and the E × B speeds were significantly less than the propagation speed of the pulse from MMS to the Van Allen Probes and GOES‐13, which is consistent with the MHD fast mode. There were increased fluxes of energetic electrons up to several MeV. Signatures of drift echoes and response to ULF waves also were seen. These observations demonstrate that even very weak shocks can have significant impact on the radiation belts.