Cluster observations of EMIC triggered emissions in association with Pc1 waves near Earth's plasmapause
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‐h...
Saved in:
Published in | Geophysical research letters Vol. 37; no. 9 |
---|---|
Main Authors | , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Washington
Blackwell Publishing Ltd
01.05.2010
John Wiley & Sons, Inc American Geophysical Union |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | 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. |
---|---|
Bibliography: | ArticleID:2010GL042648 istex:C79E133035A9FBC141EC21CA7355DC8363E8EC4D ark:/67375/WNG-247VBPSN-7 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0094-8276 1944-8007 |
DOI: | 10.1029/2010GL042648 |