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Cluster observations of EMIC triggered emissions in association with Pc1 waves near Earth's plasmapause
Author(s) -
Pickett J. S.,
Grison B.,
Omura Y.,
Engebretson M. J.,
Dandouras I.,
Masson A.,
Adrian M. L.,
Santolík O.,
Décréau P. M. E.,
CornilleauWehrlin N.,
Constantinescu D.
Publication year - 2010
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 - 10.1029/2010gl042648
Subject(s) - plasmasphere , physics , ion , atomic physics , van allen probes , cyclotron , geophysics , emic and etic , van allen radiation belt , astrophysics , magnetosphere , plasma , nuclear physics , sociology , anthropology , quantum mechanics
The Cluster spacecraft were favorably positioned on the nightside near the equatorial plasmapause of Earth at L ∼ 4.3 on 30 March 2002 to observe electromagnetic ion cyclotron (EMIC) rising tone emissions in association with Pc1 waves at 1.5 Hz. The EMIC rising tone emissions were found to be left‐hand, circularly polarized, dispersive, and propagating away from the equator. Their burstiness and dispersion of ∼30s/Hz rising out of the 1.5 Hz Pc1 waves are consistent with their identification as EMIC triggered chorus emissions, the first to be reported through in situ observations near the plasmapause. Along with the expected H + ring current ions seen at higher energies (>300 eV), lower energy ions (300 eV and less) were observed during the most intense EMIC triggered emission events. Nonlinear wave‐particle interactions via cyclotron resonance between the ∼2–10 keV H + ions with temperature anisotropy and the linearly‐amplified Pc1 waves are suggested as a possible generation mechanism for the EMIC triggered emissions.