Observations and Modeling Studies of the Effects of the 2017 Solar Eclipse on SuperDARN HF Propagation

The total solar eclipses offer a unique opportunity to study the dependence of the ionospheric density and morphology on incident solar radiation. Unique responses may be witnessed during eclipses, including changes in radio frequency (RF) propagation at high frequency (HF). Such changes in RF propagation were observed by the Super Dual Auroral Radar Network (SuperDARN) radars in Christmas Valley, Oregon and in Fort Hayes, Kansas during the 2017 solar eclipse. At each site, the westward looking radar observed an increase in slant range of the backscattered signal during the eclipse onset followed by a decrease after totality. In order to investigate the underlying processes governing the ionospheric response to the eclipse, we employed the HF propagation toolbox (PHaRLAP), created by Dr. Manuel Cervera, to simulate SuperDARN data for different models of the eclipsed ionosphere. By invoking different hypotheses and comparing simulated results to SuperDARN measurements we could study the underlying processes governing the ionosphere and improve our model of the F‐Region responses to an eclipse. This method was used in three studies to: identify the cause of the increase in the distance radio waves traveled during the eclipse; evaluate different models of change in eclipse magnitude over time; and investigate the effect of the neutral wind velocity on the simulated eclipse data. This presentation will discuss observations made by SuperDARN during the 2017 eclipse, major results from our raytrace studies, and unanswered questions that may be useful to consider when planning HamSCI’s campaign and/or similar ionospheric studies for the next eclipse over the United States in 2024.