Cluster Observations in the Inner Magnetosphere during the 18 April 2002 Sawtooth Event: Dipolarization and Injection at r = 4.6 Re

Details Cluster Observations in the Inner Magnetosphere during the 18 April 2002 Sawtooth Event: Dipolarization and Injection at r = 4.6 Re Cluster Observations in the Inner Magnetosphere during the 18 April 2002 Sawtooth Event: Dipolarization and Injection at r = 4.6 Re

May 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007agusmsm23d..06o&link_type=abstract

American Geophysical Union, Spring Meeting 2007, abstract #SM23D-06

Physics

2720 Energetic Particles: Trapped, 2730 Magnetosphere: Inner, 2740 Magnetospheric Configuration And Dynamics, 2778 Ring Current, 2788 Magnetic Storms And Substorms (7954)

Scientific paper

The present study examines a sawtooth injection event that took place around 08 UT on 18 April 2002 when the Cluster spacecraft were located in the inner magnetosphere in the premidnight sector. In association with this injection, Cluster, at a radial distance of 4.6 RE, observed that the local magnetic field became more dipolar and that both ion and electron fluxes increased without notable energy dispersion. These features were accompanied by intensifications of the equatorward component of a double-oval structure and also by an enhancement of the ring-current oxygen ENA flux. The event was also accompanied by large magnetic field (a few tens of nT) and electric field (a few tens of mV/m) fluctuations with a characteristic timescale of a few tens of seconds. These observations strongly suggest that this sawtooth injection extended not only widely in local time but also deeply into the inner magnetosphere. Interestingly, Cluster repeatedly observed dipolarization-like signatures afterward, which, however, were not associated with an enhancement of local energetic ion flux or with geosynchronous dipolarization or injection signatures. Instead, these magnetic signatures were accompanied by oscillatory plasma motion in the radial direction with a characteristic timescale of about 10 min, which appears to be related to the westward propagation of a spatially-periodic auroral structure. The associated azimuthal electric field component was well correlated with the time derivative of the north-south magnetic field component, suggesting that the observed electric field is inductive. These findings suggest that electromagnetic processes far inside geosynchronous orbit play an important role in energization of energetic ions and auroral dynamics during magnetospheric storms.

Affiliated with

Also associated with

No associations

Rating

Cluster Observations in the Inner Magnetosphere during the 18 April 2002 Sawtooth Event: Dipolarization and Injection at r = 4.6 Re does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Cluster Observations in the Inner Magnetosphere during the 18 April 2002 Sawtooth Event: Dipolarization and Injection at r = 4.6 Re, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cluster Observations in the Inner Magnetosphere during the 18 April 2002 Sawtooth Event: Dipolarization and Injection at r = 4.6 Re will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1039264