Physics of auroral phenomena : proceedings of the 33rd Annual seminar, Apatity, 02 - 05 March, 2010 / [ed.: A.G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2011. - 206 с. : ил.

Study o fhigh-latitude D-region ionosphere characteristics duringperiods ofpolar mesospheric echo (PME) appearances N + + N q = N e + N~ + Z dN d, b , N * = b t N e, ( 1 ) where N +, N q , N ~ , and N d are the positive ion, cluster, negative ion and dust particle number densities, respectively; q is ionization rate; a e, and a cl are the dissociative recombination coefficients of positive ions with electrons and clusters; (3, and у are the electron attachment and detachment coefficients; 5e, and 8,. are the flow rates o f positive ions and electrons on dust particles; Zd is the average charge of dust particles (in units of elementary charge). Note that the processes of electron attachment to oxygen molecules in triple collisions and detachment o f electrons from fotodetachment and interaction with the excited atomic oxygen quickly balance each other, so the members (ЗЛ^,, and j N ~ can be omitted. Using the expression q = a eff N 2e and equation (1) in the stationary case, we have a ^ = (1+ ^ + ^ / ) ( a e + a A + S i</A.l/), (2) where AT = N ~ / N e ; X~d = Z dN d/ N e ; a , is the weighted average rate of neutralization o f ions; 8td is the weighted average rate o f flow o f ions on dust particles. The bar is used to denote the weighted average rate for all kinds of positively charged plasma particles. Hence, the presence o f dust particles increases the effective recombination coefficient, which in turn should reduce the concentration o f electrons. Therefore, determination of the effective loss factor may be an effective method of dust determination in the mesosphere. So determining the effective loss factor in the presence of PMSE, and in his absence, from equation (2) you can get the formula (3) Nd * Z" S,„ where N e0 is the concentration o f electrons in the absence o f dust ( N d = 0). The results of the PMWE observations on facilities IS and PR are shown in Figure 3 [Osepian et al, 2007]. It shows the profile o f power IS signal (left), amplitude PR waves and electron density profile (right) during the intrusion of solar protons. Fig. 3. Comparison of incoherent scattering and partial reflection at 12:30 UT January 17, 2005 The profile power IS signal is seen a narrow peak (PMWE), corresponding to very intense reflection layer at a height o f about 70 km thick <1.5 km. At the same time, intense echoes were registered on the PR facility. A satisfactory agreement between the two radar data indicates that, perhaps, have observed the same phenomenon. According to geophysical data o f the ionosphere over the PR facility was leaking around the area of the longitudinal current [Tereshchenko et al, 2008]. The consequence could be to increase the plasma concentrations of mesospheric meteoric and formation o f thin layers, limited by sharp gradients of electron density. The electrons, shielding layers of metal ions, are no longer free. This can lead to considerable enhancement of the scattered power, because scattering of electrons becomes a collective or coherent. Using data from the two radio-physical methods of IS and PR can estimate the concentration o f meteoric ions and background plasma parameters. Thus, the presence o f intense mesospheric radioreflections during disturbances in the winter may be associated with the formation o f meteoric layers in the lower of the D-region. However, this hypothesis does not yet have convincing experimental confirmation, because the ionic composition of the longitudinal current leakage is not investigated yet. 157