Reflection of the dynamics of interplanetary space parameters in the maximum observable frequencies on different ionospheric oblique-sounding paths

Abstract

We study the correlation between variations in the solar–geophysical parameters and variations in the maximum observable frequencies (MOF) on several ionospheric short-wave oblique-sounding paths. The basic interplanetary space parameters, whose variations have the greatest impact on the MOF variations on specified paths, are determined. Variations in the Bx and Bz components of the interplanetary magnetic field (IMF) affect the MOFs on the Norilsk—Rostov-on-Don subauroral path. At mid-latitudes, the influence of the IMF components Bx, By, and Bz is significant on the Inskip—Rostov-on-Don and Irkutsk—Rostov-on-Don paths. On the Cyprus—Rostov-on-Don low-latitude path, the modulus of the IMF has the most pronounced effect. The density and velocity of solar wind manifest themselves in MOF variations on all paths. The technique of MOF retrieval by a neural network on the Cyprus—Rostov-on-Don and Irkutsk—Rostov-on-Don paths using the MOF data of the Inskip—Rostov-on-Don path is developed with allowance for the influence of the interplanetary space parameters. The retrieval efficiency of this technique is no less than 80%.