Кустов, А. В. О пороговом электрическом поле для возникновения авроральных неоднородностей с длиной волны около одного метра / А. Кустов, М. Успенский, И. Кангас ; Акад. Наук СССР, Кол. фил. им С. М. Кирова, Поляр. геофиз. ин-т. – Препр. ПГИ-87-06-60. - Апатиты : [б. и.], 1988.

Е ( х ) = £ 0 И ♦ т х ) One can в«е the E-field and electron density variations are equal each other and have opposite phases. Hence the backscatter anplitude is r 1/2 A ^ N0*< (1 - mx)2Z (x)dx - 4* fhr 1 „2 where Z(x) ~ ®XP I" 2 ^ iS standard normal distribution function. The low limit of the integral, X^. = ( E^/E q - 1 )/ ТГ) takes into consideration the "cut-off” of those ionospheric parts where the real E-field is lower than the irregularity excitation threshold. Here is the mean E-field with s*oothed fluctuations of the L-wave scales. For our estimations we assume m с 0.2 and for the homogenuous plasma - a sharp E-field threshold, E ^ = 2 0 mV/a. The latter means the EDFA should exhibit a sharp onset as it is shown on LHS of Fig.3, the dashed line. The backscatter amplitude (the same as the EDFA) as a function of the mean electric field , E^ calculated using Eq.S, grows slowly and docs not exhibit the sharp onset expected , LHS of Fig.3, solid line. He have derived such rather soft dependence from calculation in spite of the original sharp threshold at 20 aV/n which was suggested as inherent for the FB instability. Our soft EDFA model dependence is shown together with the experimental one at Fig.2, dashed line. The both dependences have a common point at E ■= 22.5 mV/m. From a general coincidence of the dependences it seems realistic to expect an exietance of the unresolved ionospheric microstr.ucture in the backecatter volume. Ue believe the ionospheric electrojet 'microstructure can <be one of causes which contributed to the distinction between real and measured quantities in the ionospheric E-field estimations from the auroral backscatter drift velocity data (Nielsen and Schlegel, 1985). In a number of papers involved in this topic many important plasaaphysical points were discussed. However they sees to have 24