A Few Science Questions that HamSCI Can Help Address During the 2023 and 2024 Eclipses

Solar eclipses are an exciting celestial event which can be used to study the terrestrial atmosphere and ionosphere systems. Locally, during a total solar eclipse, totality may only last a few minutes—and the times scales on which solar illumination decreases and then increases is much shorter that what is normally observed during sunrise and sunset. Additionally, on a larger, continental scale, the moon’s umbra moves at supersonic velocities, tracing out the path of totality. These properties serve to act as an impulse in energy on the atmosphere and ionosphere, generating a wide variety of yet to be specified (or identified) responses in those systems. 

As an example of some compelling response effects, the fast depletion-replenishment of the bottomside ionosphere (the portion of the ionosphere that is below the F-region peak) often appears asymmetric—an observation that is not well understood. Therefore, one science question which can be addressed is: will the different geometries of the 2023 and 2024 eclipses as well as the fact that they are an annular and total eclipse, respectively, have a significant effect on the asymmetry of the bottomside evolution during the eclipse? Furthermore, efforts to model and replicate the observed effects of eclipses have significantly improved in recent years; however, observations of the atmosphere and ionosphere are still required to constrain, validate, and ultimately improve our theoretical understanding of these systems. Another eclipse science question which can be addressed is: how well will these models perform for the 2023 and 2024 eclipse and how can we quantify the response of the ionosphere during these events? 

Over the past few years, HamSCI has emerged at the forefront of passive remote sensing techniques in solar-terrestrial physics. This is evidenced by HamSCI’s work using with HF timing signals and HF QSOs, show that both can be used to monitor the bottomside ionosphere on both regional and continental scales. The SEQP during the 2017 total solar eclipse was a resounding success, delivering high-impact and influential science results. Building upon that success, this technique may very well be a gamechanger for identifying and characterizing eclipse generated effects and phenomena during the upcoming 2023 and 2024 eclipses. The purpose of this presentation is to detail a few outstanding eclipse related science questions, and propose how HamSCI can lead the way in addressing them.