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## ОСОБЕННОСТИ ОТРАЖЕНИЯ СВИСТОВЫХ ЭЛЕКТРОМАГНИТНЫХ ВОЛН, ПАДАЮЩИХ НА ИОНОСФЕРУ СВЕРХУ, В ДНЕВНЫХ И НОЧНЫХ УСЛОВИЯХ

A numerical solution of the wave equations for whistling electromagnetic waves incident on the iono-

sphere from above is obtained. For the calculations, we used a matrix algorithm for the approximate solution of

wave equations in a plane-layered smoothly inhomogeneous medium and the collocation method for solving the

boundary problem. Dependences of ref lection coefficients R are obtained and analyzed on the frequency and

angle of incidence of the wave for different seasons and time of day. At night, for waves with frequencies from 1

to 10 kHz, the values of R vary from 0.1 to 0.7. In daytime conditions, the value of R, on average, is two orders of

magnitude lower and does not exceed 0.04. The smallest values of the ref lection coefficient are associated with

waves, the ref lection of which occurs in the region of strong attenuation at heights of 80–110 km. The results

obtained explain the specific features of the conditions for the excitation of the plasma magnetospheric maser.