Attention is given to an empirical model of equatorial electron density in the magnetosphere covering the L range 2.25-8. Although the model is primarily intended for application to the local time interval 00-15 MLT, a way to extend the model to the 15-24-MLT period is presented. The model describes, in piecewise fashion, the 'saturated' plasmasphere, the region of steep plasmapause gradients, and the plasma trough. Within the plasmasphere the model profile can be expressed as logne - Sigma-xi, where x1 = -0.3145L + 3.9043 is the principal or 'reference' term, and additional terms account for: a solar cycle variation with a peak at solar maximum; an annual variation with a December maximum; and a semiannual variation with equinoctial maxima.

An ISEE/Whistler model of equatorial electron density in the magnetosphere

Study of the formation of the quiet-time electron slot, which divides the radiation belt electrons into an inner and an outer zone. The pitch-angle diffusion of radiation belt electrons resulting from resonant interactions with the observed plasmaspheric whistler-mode wave band is quantitatively investigated. The effects of wave propagation obliquely to the geomagnetic field direction with the resulting diffusion at all cyclotron-harmonic resonances and the Landau resonance are evaluated along with the effects of interactions occuring at all geomagnetic latitudes. The results obtained account for the long-term stability of the inner radiation zone, the location of its outer edge as a function of electron energy, and the removal of electrons to levels near zero throughout the slot. Computed pitch-angle distributions and precipitation decay rates are in good agreement with slot-region observations.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/JA077i019p03455%4010.1002/%28ISSN%292169-9402.RADBELTS

Pitch-angle diffusion of radiation belt electrons within the plasmasphere.

The detailed quiet time structure of energetic electrons in the earth's radiation belts is explained on the basis of a balance between pitch angle scattering loss and inward radial diffusion from an average outer zone source. Losses are attributed to a combination of classical Coulomb scattering at low L and whistler mode turbulent pitch angle diffusion throughout the outer plasmasphere. Radial diffusion is driven by substorm associated fluctuations of the magnetospheric convection electric field.

Equilibrium structure of radiation belt electrons

Ring current protons turbulent diffusion in magnetospheric plasmapause, considering ion cyclotron wave lifetime and geomagnetic storms

Turbulent loss of ring-current protons.

Semiempirical analytic formulas for large-scale electric magnetospheric fields are developed that are valid within the inner magnetosphere as well as within the ionosphere. These electric fields drive ionospheric electric currents. Moreover, field-aligned electric currents must exist in order to maintain the magnetospheric electric field configuration. The model calculations are compared and are shown to be consistent with the shape of the plasmapause, the equivalent electric current systems of DP 1 and DP 2, the available electric field observations at ionospheric altitudes, and the observations of field-aligned electric currents.

A semiempirical model of large‐scale magnetospheric electric fields

Magnetic activity effect on magnetospheric plasmapause position, measuring ion concentrations as function of local time from OGO 5 observations

A study of the influence of magnetic activity on the location of the plasmapause as measured by OGO 5

Plasmasphere bulge region morphology from hydrogen ion concentration measurement by mass spectrometer on OGO 5 satellite

The morphology of the bulge region of the plasmasphere

The concentrations of H(+) ions in the dayside region of the plasmasphere, measured from March 1968 through February 1969 by the Lockheed light-ion mass spectrometer aboard the OGO 5 satellite, are presented and analyzed. The position of the plasmapause on the dayside appears to be determined by the level of magnetic activity present during the previous corotation of the dayside sector through the formative nightside region. Observations of the buildup of H(+) density versus local time following magnetic storms indicate that H(+) ions flow from the dayside ionosphere into the plasmasphere and plasma trough. Plasmapause density profiles in the afternoon-dusk sector show the effects of the dayside filling from the ionosphere. In addition, several of the dayside profiles display a steep drop in the H(+) density of about a factor of 10 inside the plasmapause position.

The dayside of the plasmasphere

Plasmapause observations by ion spectrometer aboard OGO-5 vehicle for early orbits, obtaining O, He and H ion concentration profiles for geomagnetic parameter

Observations of the plasmapause from OGO 5

Hydrogen ion concentration measurements by OGO 5 in plasmasphere during intense magnetic storms accompanied by stable auroral red arcs

G. W. Sharp

Papers

A study of the influence of magnetic activity on the location of the plasmapause as measured by OGO 5

The morphology of the bulge region of the plasmasphere

The dayside of the plasmasphere

Observations of the plasmapause from OGO 5

Ogo 5 measurements of the plasmasphere during observations of stable auroral red arcs