Global Dynamic Model of Critical Frequency of the Ionospheric F2 Layer

Abstract

A global dynamic model of the F2 layer of the ionosphere GDMF2 is designed to calculate foF2 in both quiet and geomagnetically disturbed conditions. The term “dynamic model” implies that the change in foF2 at middle, subauroral, and auroral latitudes depends on the current level of geomagnetic activity with consideration of the prehistory of its development. A distinctive feature of this model is the empirical approach used to create the median (background) model of foF2 for quiet geomagnetic conditions and a number of aeronomic corrections to it related to the formation of the main ionospheric trough and the auroral peak of electron density, as well as changes in the temperature and composition of the thermosphere. All of these corrections depend on the changes in the heliogeophysical conditions. The global dynamic foF2 model demonstrates considerable improvement as compared to IRI-2016 (with the option ‘STORM = ON’) by on average of ~16% at high and middle and ~7% at equatorial latitudes.