Структура и динамика полярных токовых систем : материалы международного симпозиума «Полярные геомагнитные явления», 25-31 мая, Суздаль, СССР / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т. – Апатиты : [б. и.], 1988.

The instability arises when (8) has the solution limited in x, monotonic at x — *• + o-=> , and depending on уas little as n or p. In the case when the dependence on уin (8) may be neglected we obtain for the disturbances with wavelengths x < T x * + J « w T f i p u = 0 ( 9 ) at j°(x)>0 (9) takes the form of the Schrodinger equation for the potential well, so the instability condition reduces to the condition for the existence of the levels. The well depth determines the number of arcs. The main parameter of the problem is Г= j0 е/1рЭ€2 Т| , where эе-1 is the characteristic width of the outflowing current region, JQ is its amplitude. Г is related to the electric field jump [E] across the band as where P(ac x)=j°/j0 . The allowance for the field-line nonequipotentiality entails the substitution г -*• reff . In the case (2) and of the ion distribu tion function different from Maxwellium and having a peak (connected with the magnetosphere filling by the ionospheric ions), we have reff = Г[-1 - 3 je'T ) where S - i is determined by the form of the ion distribution function. High values of Ге^ occur when the denominator in (11) is nearly zero. The value of Г = 6, which is necessary for the arc to double, may be attained disregard ing the potential difference between the magnetosphere and the ionosphere. The value of Г =20 necessary for the arc to treble requires that the magnetic field lines nonequipotentiality should be allowed for. 1. Tverskoy B.A. On the electric fields in the Earth's magnetosphere. - Dokl.Acad.Nauk USSR, 1969, v.188, И 3, p.575-578. 2. Tverskoy B.A. Electric fields in the magnetosphere and the origin of trapped radiation. - In: Solar-Terrestrial Physics, 1970, Dordrecht, Holland. Ed. E.R.Dyer, 1972, p.297-317. 3. Vasyliunas V.M. The interrelationship of magnetospheric processes, - In: Solar-Terrestrial Physics, Dordrecht, Holland. Ed.E.R.Dyer, 1972, p.29-38. 4. Tverskoy B.A. On the field-aligned currents in the magnetosphere. - Geomagn.and Aeronomy, 1982, v.22, H 6, p.991-995. 5. Knight S. Parallel electric fields. - Planet.Space Sci., 1973, v.21, N 5, p.741-750. 6. Antonova E.E., Tverskoy B.A. On the nature of the "inverted V" electron precipitation band and the Harang discontinuity in the dusk sector of the auroral ionosphere. - Geomagn.and Aeronomy, 1975, v.15, N 1, p.105-111. 7. Antonova E.E. About the reason for the linear dependence of the field- aligned electron current outflowing from the ionosphere on the field-aligned potential difference. - Geomagn.and Aeronomy, 1981, v.21, N 6, p . 1004-1008. 8. Antonova E.E. About the large-scale double layer. - Geomagn.and Aeronomy, 1979, v.19, N 5, p.877-883. ( 10 ) R E F E R E N C E S : 42