Analysis of Reflection Height Descent in Ionospheric Heating Experiments

Using the high-power heating and diagnostic equipment of the European Incoherent Scatter Scientific Association (EISCAT), we conducted ionospheric heating experiments on September 13, 2010, ionic line enhancement characteristics observed using VHF radar. The study found that as the heating process progresses, the altitude of the ion line enhancement phenomenon gradually decreases. Through analysis of electron density and electron temperature, we propose that the underlying physical mechanism of this phenomenon may be the enhancement of diffusion transport processes. Specifically, electron diffusion drift alters the electron density near the reflection altitude, causing a step-like decrease in altitude. This result is not due to an increase in electron temperature affecting the electron recombination rate.