COMPARISON OF LONG-TERM ANTARCTIC OBSERVATIONS OF SCHUMANN RESONANCE WITH CALCULATIONS ON THE BASIS OF A TWO-COMPONENT OTD-MODEL

Abstract

Organization of continuous observations of Schumann resonance (SR) opens up the possibility of permanent monitoring the lower ionosphere and global storms. The existing methods for monitoring thunderstorm activity with SR are developed in detail only for point sources. However, the current models of radiation sources are too simplistic. In this connection, the development of semi-empirical source models, in which the intensity distribution is determined by the data from satellite observations of global storms, becomes very important. The paper compares the long-term experimental SR data accumulated in the Ukrainian Antarctic Station “Akademik Vernadsky” with the results of calculations of SR in the two-component OTD-model. It is shown that the model, despite the detailed distribution of lightning sources according to optical observations from space, is consistent with the experiment only partially. On the daily time scale, the two-component OTD-model quite well reflects the position of the main maximum of the global storms and their intensity, but the position of individual sources is described not precisely enough for an adequate representation of the diurnal variations in peak frequencies. The model describes quite well the annual and interannual variations in peak frequency of the magnetic components Hy. It is shown that the inter-annual variations of peak frequencies can be attributed to a change in height of the ionosphere and drift sources from year to year, and the long-term drift of the peak frequency is associated with the modification of the ionosphere during solar cycle.

Keywords

• peak frequencies
• schumann resonance
• thunderstorm activity
• worldwide lightning models