[en] The change of energy of a collisionless, two-fluid plasma consists of the adiabatic gain or loss of energy, which is due to the work done by the electromagnetic forces, and of the non-adiabatic change associated with the presence of the 'rest' field Esup(*) = E + (1/c) V x B. An expression is presented for the non-adiabatic gain or loss of energy per unit time and volume. A special case of non-adiabatic energization of a slowly convecting plasma sheet plasma is discussed in some detail. Regardless of the value of V, the non-adiabatic energization may significantly exceed any conceivable energization associated with the electric field -(1/c) V x B. (author)

[en] Energetic neutrals in dissociative recombinations near or above the exobase provided an important component of exospheric density and escape fluxes. Plasma thermal velocities provide the main contribution to the velocity spread and an exact integral for the escape flux applicable in marginal cases is found for a simple atmosphere and collisional cut-off. Atomic fragments from recombination of diatomic oxygen and nitrogen ions in the Venus and Mars atmospheres are examined and density integrals derived. The oxygen escape flux on Mars is half that previously estimated and there is very little isotope preference supplementing diffusive separation. However, escape of the heavier ¹⁵N isotope is low by a factor two. Reinterpretation of its 75% enrichment as detected by Viking leads to a range 0.4-1.4 mbar for the primeval nitrogen content on Mars. (author)

[en] In this paper a model is presented for the Earth's ionosphere and plasmasphere, allowing for the inertia and anisotropic energy distribution of thermal plasma. A procedure for simultaneous solution of equations of continuity and motion for the O⁺ and H⁺ ions, subject to inertia terms, is described. The model also includes transfer equations for longitudinal and transversal thermal energies. The system of simulating equations and the kinetic equation for superthermal electron spectra are concordantly solved along geomagnetic field lines. Within the framework of the model a study is made of the dynamics of filling of the evacuated plasmaspheric reservoir after a magnetospheric disturbance. It is shown that the filling of the tubes of force with L >= 3.5 proceeds with supersonic speeds during the first several days and the character of filling differs very much from a diffusion-equilibrium one. The spatio-temporal behavior of electron and ion temperature anisotropy that is formed in the process of filling, is considered. It is found that the value of electron anisotropy can be large. A brief analysis is made of the causes of electron and ion temperature anisotropy. (author)

[en] The paper considers the energy spectrum of particles accelerated near X-point of the magnetic field in the course of the tearing instability development in the current layer. The time dynamics of the spectrum at the linear and nonlinear stages of the instability is studied. The contribution of the particles inflowing into the vicinity of the magnetic X-point due to drift in the crossed electrical and magnetic fields was also taken into account. The dynamics of particle acceleration is numerically simulated and the results of the simulation are compared with the theoretical model. The analytical and numerical calculations are in reasonable agreement with the results of IMP satellites 7 and 8 energetic proton measurements in a wide energy interval. (author)

[en] This paper describes a DMSP data set of 150 auroral images during magnetically quiet times which have been analyzed in corrected geomagnetic local time and latitudinal coordinates and fit to offset circles. The fit parameters R (circle radius) and (X, Y) (center location) have been compared to the hourly interplanetary magnetic field (IMF) prior to the time of the satellite scan of the aurora. The results for variation of R with Bsub(z) agree with previous works and generally show about a 1⁰ increase of R with increase of southward Bsub(z) by 1 nT. The location of the circle center also has a clear statistical shift in the Southern Hemisphere with IMF Bsub(y) such that the southern polar cap moves towards dusk (dawn) with Bsub(y) > (Bsub(y) < O). (author)

[en] In the midday sector, the hard electron precipitation and the associated patchy aurora at geomagnetic latitude approximately 65⁰ are the only auroral features (approximately 20 keV) located equatorward of the dayside auroral oval during intense and moderately disturbed geomagnetic conditions. The patchy luminosity in the midday and late morning sectors are identified as the active mantle aurora. The precipitating electrons reside mostly at energies greater than several keV with an energy flux of approximately > 0.1 erg cm^-2 s^-1 during geomagnetic active periods. This hard precipitation occurs in a region which is asymmetric in L.T. with respect to the noon meridian. The region extends from the morning sector to only early afternoon (13-14 M.L.T.) along the geomagnetic latitude circle of about 65-70⁰. The model calculation indicates that the mantle aurora is produced by the precipitation of the energetic electrons which drift azimuthally from the plasma sheet at the midnight sector to the dayside magnetopause during magnetospheric substorms. (author)

[en] Fabry-Perot interferometer measurements of Doppler shifts and widths of the 630.0 nm nightglow line have been used to determine the neutral winds and temperatures in the equatorial thermosphere over Natal, Brazil during August-September 1982. During this period, in the early night (2130 U.T.) the average value of the horizontal wind vector was 95 m s^-1 at 100⁰ azimuth, and the temperature varied from a low of 950 K during geomagnetically quiet conditions to a high of approx. 1400 K during a storm (6 September). The meridional winds were small, < or approx. 50 m s^-1, and the eastward zonal winds reached a maximum value 1-3 h after sunset, in qualitative agreement with TGCM predictions. On 26 August, an observed persistent convergence in the horizontal meridional flow was accompanied by a downward vertical velocity and an increase in the thermospheric temperature measured overhead. Oscillations with periods of 40-45 min in both the zonal and vertical wind velocities were observed during the geomagnetic storm of 6 September, suggesting gravity wave modulation of the equatorial thermospheric flow. (author)

[en] Plasma and magnetic field data from PROGNO2-7 show that solar wind (magnetosheath) plasma elements may penetrate the dayside magnetopause surface and form high density regions with enhanced crossfield flow in the boundary layer. The presence of a local plasma in the boundary layer is shown to have important consequences on the energy transfer process, since a significant fraction of the excess momentum of the infected magnetosheath plasma may be taken up by the local plasma. This local plasma comprises a hot magnetospheric component of ring-current origin and a ''cold'' component with an ion composition resembling that in the plasma source. It is shown that the dynamics of the accelerated ''cold'' ion drift beams may reflect both the boundary layer energy transfer process and the magnetosheath plasma penetration through the magnetopause. (U.K.)

[en] The polar cap magnetic activity MAGPC-index characterizing the intensity of disturbances affected by the IMF vertical component was derived from the antarctic station Vostok data in accordance to method of Troshichev et al. (1979a). The paper examines the statistical relationship between the 15-min values of this index and interplanetary quantities such as IMF components, solar wind velocity, interplanetary electric field and others. The results of the computation show a good correlation of MAGPC indices with interplanetary quantities including the IMF southward component. The best correlation is obtained for the merging electric field. The conclusion is: the MAGPC index derived from the background magnetic data may be used for monitoring of the convection electric field in the polar cap. (author)

[en] The anisotropy of 35-1000 keV ions in two corotating particle events associated with high-speed solar wind streams at 1 AU is examined in terms of the diffusion-convection propagation model using data from the Energetic Proton Anisotropy Spectrometer on ISEE-3. The calculated diffusive anisotropy in the solar wind frame is found to be sunward and closely field-aligned, with a nearly energy-independent magnitude of approx. 40%. For one stream, using the Voyager 2 data of Decker et al.(1981), a positive gradient of approx. 100%/AU is found for >approx. 50 keV ions between 1 and 4 AU. The observations do not appear to support the scatter-free propagation model and indicate that ions with energies as low as a few tens of keV may be in diffusive equilibrium with the solar wind in this class of events. (author)