The Plasma Mantle: Polar Satellite Observations
Abstract
Since launch in February 1996, the Polar satellite has made numerous traversals of the high-latitude dayside magnetosphere. These traversals have covered the high-altitude regions of the low-latitude boundary layer, cusp, cleft, mantle, and polar cap. Often, as the Polar satellite traverses the high-latitude dayside magnetosphere, it leaves the soft precipitation region of the cusp or cleft and enters into the mantle plasma. There, the angular distribution of 1 to 10 keV ions changes character from a convecting near-isotropic one to convecting predominantly perpendicular ions that are weakly upflowing. Sometimes the predominantly perpendicular fluxes of ions are observed throughout the cusp, cleft, and mantle. These 'trapped' ion signatures are relatively common, and the energy of the trapped ions is generally < 10 keV. The energy of the most poleward trapped population generally decreases with increasing latitude as is expected for the mantle plasma. The angular distributions of the downward-going < 10 keV ions have large 'loss cones', indicative of a relatively weak mirror geometry in the magnetic field at high altitudes. The mantle ion fluxes observed on Polar show much the same flows, distributions, and spatial characteristics as those observed on HEOS Rosenbauer et al., 1975. The composition of the ions at > 1 keV/q is predominantly solar wind as expected.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 20, 1998
- Accession Number
- ADA385553
Entities
People
- Caroline Perry
- James Roeder
- Joseph F. Fennell
- M. Grande
- R. Friedel
Organizations
- The Aerospace Corporation