Ionospheric Ion Beam Accelerations Above the Polar Cap

Details Ionospheric Ion Beam Accelerations Above the Polar Cap Ionospheric Ion Beam Accelerations Above the Polar Cap

Dec 2004

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004agufmsm21a0444m&link_type=abstract

American Geophysical Union, Fall Meeting 2004, abstract #SM21A-0444

Physics

2451 Particle Acceleration, 2712 Electric Fields (2411), 2776 Polar Cap Phenomena, 2784 Solar Wind/Magnetosphere Interactions

Scientific paper

We present a Cluster multi-experiment study of near mono-energetic ion beams inside the polar cap. Data are taken at altitudes of 4 - 7 Re. Using the Cluster mass spectrometers a clear distinction is made between ion beams ejected from the polar cusp and those ejected along the local magnetic field line passing by the spacecraft. Polar cusp beams are characterized by the encounter of field aligned proton and oxygen ions with energies differing by a factor of about 4, as expected from the velocity filter effect. Polar cap local outflowing beams are characterized by a series of nearly monoenergetic ion inverted V structures in the 100 eV to ~ 3 keV range. Ions are field aligned and in many occasions the structures are associated with a converging electric field. The field aligned potential drop fits quite well the ion energy profile. No ion precipitation is recorded. In several cases comparisons of ion and electron distributions show that the parallel electric field is weak and can extend to altitudes higher than that of the satellite. Detailed analysis of the ion energy distribution show that oxygen ions are more energetic than protons and that outflowing ions are heated during their parallel acceleration. As for the auroral region, these observations could be due to an ion two-stream instability. We present the correlation of these events with the IMF orientation and use DMSP data to show the simultaneous occurrence of polar rain over the polar cap.

Affiliated with

Also associated with

No associations

Rating

Ionospheric Ion Beam Accelerations Above the Polar Cap 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 Ionospheric Ion Beam Accelerations Above the Polar Cap, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ionospheric Ion Beam Accelerations Above the Polar Cap will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1465452