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Destiny of earthward streaming plasma in the plasmasheet boundary layer
Author(s) -
Green James Lauer,
Horwitz James L.
Publication year - 1986
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl013i001p00076
Subject(s) - magnetosphere , ring current , physics , earth's magnetic field , geophysics , convection , electric field , proton , ionosphere , boundary layer , pitch angle , geomagnetic storm , earth radius , field line , plasma sheet , substorm , plasma , computational physics , atomic physics , magnetic field , mechanics , nuclear physics , quantum mechanics
Propagation characteristics of earthward streaming protons in the plasmasheet boundary layer are investigated in a model magnetosphere from the analysis of single particle trajectories. The phase space of initial proton distributions within the plasmasheet boundary layer out to 40 Earth radii (R e ) can be separated into four major components. In a region outside the loss cone, protons with pitch angles less than about 2.6° can make it to the auroral zone at S3‐3 altitudes and below. Protons at all other pitch angles, with speeds greater than about 1100 km/s, reflect (or mirror) at high latitudes near the Earth and return tailward, often convecting toward the inner plasmasheet. Protons with velocities as high as 800 km/s, regardless of pitch angle, are found to mirror such that they are "trapped" in the ring current region of the magnetosphere. These results are dependent on the magnitude and direction of the convection electric field, such that during geomagnetic storms with higher convection electric fields, higher energies of the plasmasheet boundary layer protons would be expected to reach the low‐latitude portions of the ring current.