N. F. Pissarenko

Ion acceleration in the Martian tail: Phobos observations

The measurements carried out on the spacecraft Phobos-2 have revealed that the plasma sheet of the Martian magnetosphere consists mainly of ions of planetary origin, accelerated up to ∼ 1 keV/q. Such an acceleration may result from the action of magnetic shear stresses of the draped field, the ion energy increasing toward the center of the tail where magnetic stresses are stronger. The energy gained by heavy ions does not depend on their mass and are proportional to the ion charge. The mechanism of the ion acceleration is related with the generation of a charge separation electric field, which extracts ions from “ray” structures in the Martian tail.

INTERBALL/Tail observations of high latitude pressure distribution

Abstract The determination of the real high latitude ring current distribution can be made if radial and azimuthal plasma pressure gradients are known. At high latitudes the plasma pressure is nearly isotropic, its calculation requires measurements of particle fluxes in the energy range from 0.1 to the hundreds of keV. Plasma pressure along the trajectory of INTERBALl/Tail Probe was calculated using data of CORALL and DOK-2 devices. It is shown that in most cases plasma pressure increases with the decrease of geocentric distances. The case is selected when pronounced pressure plateau is observed.

Magnetospheric plasma pressure and space weather

Abstract The atmospheric pressure is the main parameter measured for ordinary weather prediction. Plasma pressure is the main parameter determining the equilibrium of the magnetosphere, structure of the transverse and field- aligned currents. Transverse currents determine the value of D st -variation. Field-aligned currents determine the large-scale ionospheric electric fields and plasma transport. So the obtaining of magnetospheric plasma pressure distribution can be one of the main step in the solution of space weather problem. INTERBALL/Tail observations are used for determination of plasma pressure distribution with rather high accuracy.

The Structure of Ion Spectra in Outer Regions of the Ring Current: The November 13, 1995 Event

We present the results on variations of ion spectra in the energy range from 1 keV to 3 MeV. The spectra measured onboard the INTERBALL Tail Probe satellite on November 13, 1995, during the satellites passage from the dipole field lines to the lines stretched into the magnetotail are analyzed. The data of the CORALL, DOK-2, and SKA-2 instruments are used to reconstruct the ion spectra. It is shown that, when the ion spectrum along the satellite trajectory is averaged over 2-min intervals, it is smooth up to geocentric distances of 6RE. With decreasing distances, the form of the particle spectra in the region under consideration remained virtually unchanged (region from L = 11RE down to L= 6RE) and only insignificant variations of the energy of the spectral maxima are observed. Possible reasons for the observed regularities are discussed.