Variation of the Plasma Sheet in the Near-Earth Magnetotail by the Impact of an Interplanetary Shock
Abstract
It has been reported that Earth's magnetosphere is compressed by the impact of an interplanetary shock. ULF waves or pulses of electric fields are induced in the inner magnetosphere by the impact, which can energize radiation belt particles. In this study we report the observations of the plasma sheet in the near-Earth magnetotail around ~-17 RE by the Cluster spacecraft when an interplanetary shock impacts Earth's magnetosphere. On 24 August 2005 an interplanetary shock impacted Earth's magnetosphere and induced a storm sudden commencement (SSC) and a magnetic storm. After the SSC both the density and temperature of plasmas in the near-Earth magnetotail significantly increased. The current density in the plasma sheet also increased, which implies that the plasma sheet was compressed. The increase of the particle fluxes of ions and electrons was measured predominantly for E > ~30 keV up to ~100 keV, which is much lower than the energies of the particles observed in the radiation belt. The flux enhancement was more prominent for electrons than ions, which suggests that the energization is more efficient for electrons than ions. These observations show that the plasma sheet in the near-Earth magnetotail is affected by the impact of an interplanetary shock, but some aspects are different from those observed in the inner magnetosphere.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMSM11D2326L
- Keywords:
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- 2139 INTERPLANETARY PHYSICS / Interplanetary shocks;
- 2764 MAGNETOSPHERIC PHYSICS / Plasma sheet;
- 2784 MAGNETOSPHERIC PHYSICS / Solar wind/magnetosphere interactions;
- 7846 SPACE PLASMA PHYSICS / Plasma energization