Электродинамические процессы в высоких широтах: материалы междунарордного симпозиума «Полярные геомагнитные явления», 25-31 мая 1986 г., Суздаль, СССР / Междунар. геодез. и геофиз. союз, Междунар. ассоц. геомагнетизма и аэрономии ; Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т ; [редкол.: О. М. Распопов (отв. ред.). и др.]. - Апатиты : Кольский филиал АН СССР, 1988.

situation is not complicated b y wave he a ting of the plasma and where it has b e e n known for some time that wave phase speeds are equal to the ion-acous- tic speed (Parley,1986 h as recently reviewed this subject), Sudan (1983) has r ecently explained this l atter result and, at the same time, has accounted for the stabilization о S, the P arley-Buneman instability by including re s o n ance b r oadening effects w h i c h arise because of electron scattering by waves (Dupree, 1 9 6 8 ). Sudan's resu lt i n g nonl i n ea r dispersion relation, wh i ch replaces equation 2 , is к V where Н'= '»еѵі /ЛвЛ( , V ' ^ W - J S l g S l i a nd is an effective electron-wave collision frequency. The i nterpretation of equat i o n (3) is simply that electron scattering b y F arley-Buneman waves reduces the w a v e s 1 phase speed to its threshold value ( * с ), a n d hence terminates unstable growth. Pr o m equation 3 we may s write (4) Fo r typical E - r eg i o n conditions w h e n Parley - B un e m an waves are strongly excited, then 7 » l ' »e Not i n g this result, Primdahl a n d B a n s e n (1986) were lead to suggest that the strong wave h e a ting at h i g h latitudes might be explained by replacing \)e b y V * i n the usual electron he a ting rate: a = \>*nmeE*/e4 R o b in s o n (1986) has demonstrated theoretically that w h e n resonance broadening effects are included i n the electron energy a n d m o m en t u m balance equations that enhanced h ea ting similar to that suggested b y Primdahl and B a h na e n (l 9 8 6 ) does i ndeed result. R o b in s o n (1986) has adopted a f o rmalism in w h i c h Parley- B u n e m a n waves are treated as a plasraon gas. H is expression for the electron h ea ting rate due to e l e ot ron-plasmon collisions is & =\)*птв(¥гі- C s )* (5) where Cg = c g£ and £ is a unit v e ct o r in the direction of wave propagation. E x p r e ss i o n (5) is entirely a n alogous to the usual expression for electron neutral friction h e at i n g (v * •*-»>),, , a n d £ s '** 2 n )* An. important consequenoe o f‘.wave h ea ting is to increase c g in e xpres sion (3) a nd consequently to inorease the phase speeds of Farley-Buneman waves. U s i ng expressions 3, 4 a nd 5 R o b i n so n has calculated the phase v e l o city cg of stabilized Parley - B un e m an wav e s as a function of v d i n a n entir e ly self-consistent manner. The res u l ti n g variations of o a w i t h v d (Pig.10) are found to consistent w i t h the ra da r observations reported b y N i e l s e n and Schlegel (1985). Alth o u gh the n e w self-consistent nonlinear theory of radar auroral b a c k scatter outlines above can satisfactorily e xp lain a n u m be r of rad a r observa tions it must still regarded as a tentative first step towards a more ri g o rous and comprehensive t heory w h i c h w o u l d n e e d to include, for example, k |( (St.-Maurice and Laher,1985) and wave propag at i o n effects (M o o reroft,1 9 84 s S t. - M a ur i c e, 1985). I n this w a y it m a y be possible to improve our und e r st a n ding of a whole range of observations such a s r ad a r cross-sections (Oksman et al.,1986), radar spectral w idths (Schlegel et al.,1986), radar aspect 8 6