Полярные геомагнитные возмущения и связанные с ними явления : материалы международного симпозиума «Полярные геомагнитные явления», 25-31 мая 1986 г., Суздаль / Междунар. геодез. и геофиз. союз, междунар. ассоциация геомагнетизма и аэрономии, АН СССР, КНЦ, ПГИ. – Апатиты : [б. и.], 1989.

measurements. Our calculations are based, on a n e w approach for deriving a solitary wave solution a n d a more adequate, from our point of view, numerical procedure f o r solving the ion-density equation. D e s c ription of the m o d e l . Fo r the description of the wave propagation in the neutral component ,a model ia proposed for long, horizontally propagating long-period solitary w a v e s w i t h ver t i c a l l y stratified amplitude functions and wave functions A(x,t) satisfying the Korteweg-de Vries equation w i t h integral coefficients (D a n o v , 1986 ). See Ap p e n d i x for details. The viscose dissipation iB not taken into account since it is we a k and does not affect the pr o p a g a tion of the wa v e s f r o m the polar oval to the equator. The Coryolis forces are not considered as well because the wave period is smaller than the period of planetary waves. The i o n drag is a significant effect actually, but it is not a subject of the present i nvestigation an d is neglected here. Ionospheric m o d e l . If we suppose that the ionization density slightly depends on the h o r izontal coordinates, then the continuity equ a t i o n for N takes the form: where Кsin I (Ti +■T e) , 1 “ т1^п & 2 q sin I Кsin I 9 , , . Э й , . „ . э а 2 d z Here I is the m a g n e t i c field inclination, is the i o n mass, T^ an d T e are io n a n d e l ectron t emperatures depending o n the m e a n temperature T, is the collisional fre q u e n c y between i o n and neutral components depending on p , T; q is the i o n p r o d u c t i o n rate; the reco m b i n a t i o n rate 1 is determined by 1 = ---—--- N . (2) I n the h i g h layers of the ionosphere o £ n »£> and 1 is linear fun c t i o n of N , i.e. 1 = ji N , and i n the lo w layers ofN<<jb and 1 = o C N 2 . Since we c onsider the p r o cesses in the heights fr o m 120 to 700 km we have no right to make simplifying supposition a n d is g i v e n by relation (2). The f o l l o w i n g b o u n d a r y conditions are u s e d in solving equations (1)» the ion i z a t i o n density is zero at the lower boundary, i.e. N (120)»0 and the flux is i mposed at the up p e r layer as a f u nction of the temperature. In this way: N = 0 Z = 120 кт, ( 3 ) 9 n ; sin I ( G 1 •+ Gr2 N) =-Ф ( T - T * ) z. = 700 кт, where <t> is constant, is a m e a n temperature (diurnal). Differential iterational m e t h o d is u s e d to d e termine the stationary profile of the ion i z a t i o n density. The profile of N is shown i n Fig.7a before re a c h i n g the nec e s s a r y a cc u r a c y a n d i n Fig.7b af t e r the a c c u r a c y is reached. The calculations correspond to the unp e r t u r b e d state of the above men t i o n e d case f r o m the 96