Cluster observations of EMIC triggered emissions in association with Pc1 waves near Earth's plasmapause

J.S. Pickett (1) , B Grison (2) , Y Omura (3) , M. J. Engebretson (4) , I Dandouras (5) , A Masson (6) , M.L. Adrian (7) , O Santolík (8) , Pierrette Décréau (9) , N Cornilleau‐wehrlin , D Constantinescu (10)

1 Department of Physics and Astronomy [Ames, Iowa]
2 IAP - Institute of Atmospheric Physics [Prague]
3 RISH - Research Institute for Sustainable Humanosphere
4 Department of Physics [Minneapolis]
5 CESR - Centre d'étude spatiale des rayonnements
6 RSSD - Research and Scientific Support Department, ESTEC
7 GSFC - NASA Goddard Space Flight Center
8 Faculty of Mathematics and Physics [Praha/Prague]
9 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
10 Department of Applied Mathematics, Association Euratom-MECI

[1] 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. Citation: Pickett, J. S., et al. (2010), Cluster observations of EMIC triggered emissions in association with Pc1 waves near Earth's plasmapause, Geophys. Res. Lett., 37, L09104,

Domaines: Planète et Univers [physics]

J.S. Pickett, B Grison, Y Omura, M. J. Engebretson, I Dandouras, et al.. Cluster observations of EMIC triggered emissions in association with Pc1 waves near Earth's plasmapause. Geophysical Research Letters, 2010, 37, L09104 (5 p.). ⟨10.1029/2010GL042648⟩. ⟨insu-01180901⟩