Observations of Solar Eclipse-Induced Variations on Ionosphere F2 Layer Critical Frequencies

On April 8th of 2024, a total solar eclipse was observed crossing over North America with a path of totality across 13 U.S. states. This eclipse provided a unique opportunity to observe the various effects that a reduction in solar radiation can have on the earth's upper atmosphere which is otherwise known as the ionosphere. Using GIRO Digisonde data and the SAOExplorer software from various ionosondes located across The United States, I observe the impact of these event on what is known as the F2 layer of the ionosphere more specifically, the impact on the critical frequency of this layer. The F2 layer is 200-400 km altitude and plays a crucial role in radio wave propagation. Critical frequency is the maximum frequency at which radio waves will be refracted back down to earth without penetrating through the ionosphere and escaping into space. We will observe whether a solar eclipse will have an impact on the critical frequency by utilizing ionosonde measurements like electron density and height. Additionally, we compare the April 8, 2024 Total Eclipse Data to the October 14, 2023 Annular Solar eclipse to understand whether the type of eclipse results in varied ionospheric impact. Based on the data we obtained, our results suggest that rather than eclipse type, a more stable variable to observe is the eclipse percent obscuration which suggests a higher steady decrease in NmF2 and f oF2 with a higher obscuration rate. Overall, this work will help to advance our understanding of this space weather phenomena which will in turn have more practical applications for radio communications.