A region of density enhancements of thermal heavy ions (O+, O++, and N+) has been observed on numerous occasions by the retarding ion mass spectrometer on the Dynamics Explorer 1 satellite. Outer plasmasphere densities of heavy ions are often observed to be up to 2 orders of magnitude higher than equatorward densities within an orbital pass. This phenomenon is almost always observed in the region of the plasmasphere just inside the plasmapause and has been seen at all local times. A statistical study of these heavy ion density enhancements, covering almost 600 passes of DE 1 through the plasmasphere, shows that O+ and O++ enhancements occur over about 64% of the observed passes, with the highest frequency of occurrence being found in the late evening and morning regions. O+ enhancements tend to be seen more frequently in the morning, while O++ enhancements are more likely to be observed in the evening. O+ appears to have a higher outer plasmasphere density enhancement than O++ in all local time regions. Evidence showing that the L shell of the heavy ion density enhancement peaks is dependent upon Dst is presented. Finally, mechanisms for the creation of the heavy ion density enhancements are briefly discussed, including the “geomagnetic mass spectrometer” and plasmapause‐associated electron heating of the topside ionosphere.

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A field is represented by its Fourier modes u(k, t) on the wave-number interval 0~k + k,". We seek to reduce the number of degrees of freedom needed to describe the system by eliminating those modes in the band of wave numbers k, k~k, ", the u+, while retaining their average effect on the remaining modes, the u . Because of mode-mode coupling, this requires, in principle, a conditional average over the u+, in a subensemble in which the u are held (approximately) constant. The conditional average can be related to the full ensemble average by means of the decomposition u+ =v++ 6+, where v+ is independent of u but has the same global mean properties as u+, while h, + represents the effect of mode coupling on the conditional average. Implementation of the formalism for any particular physical system requires an ansatz for the relationship between v+ and u+ such that the conditional average of h, + is small. This procedure is illustrated by its application to the Navier-Stokes equation, where v+ is taken to be the first-order expansion of u+ in a Taylor series about k = k,", thus permitting a renormalization group ca-lculation of the turbulent effective viscosity, as reported previously [Phys. Rev. Lett. 65, 3281 (1990)]. For systems like thisw, ith deterministic time evolution, the conditional average must be based on the weak, or imprecise, condition that u +4 is held constant, where 4 is small (but not zero) and has zero mean under the conditional average, in order to ensure chaotic u+. We show that our formalism, relating conditional and full ensemble averages, is independent of @ to second order in small quantities.PACS number(s): 05.20. -y, 05.45.+b, 47.25.Cg

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Electron and plasma beams and neutral gas plumes were injected into the space environment by instruments on Spacelab 1, and various diagnostic measurements including television camera observations were performed. The results yield information on vehicle charging and neutralization, beam-plasma interactions, and ionization enhancement by neutral beam injection.