Collaborative Research: Remote Sensing of the Lower Ionosphere during 2024 Solar Eclipse: Revealing the Spatial and Temporal Scales of Ionization and Recombination

University Of Colorado At Denver, Aurora CO

Investigators

Abstract

This award involves a collaboration between the University of Colorado Denver and University of California Berkeley to study the ionosphere during a solar eclipse. Very low frequency radio observations will be made during the 2024 solar eclipse in the eastern United States. A solar eclipse is a rare event in which the radiation from the sun is partially or totally obscured by the moon for a few minutes. A solar eclipse is not only spectacular to observe but also provides a rare opportunity to study the physical and chemical processes of the ionosphere. In particular, the lowest part of the ionosphere is significantly modified by the sun and is difficult to study. A solar eclipse offers the opportunity to observe a day-night-day change of the ionosphere on the scale of a few minutes. Observations made during an eclipse therefore provide a key insight into how the sun changes the lower ionosphere. Understanding the lower ionosphere is important to improving long distant communications and understanding space weather processes that affect an increasing number of technologies. A number of students from the diverse populations at both universities will support the effort and be trained to make low frequency radio wave observations and their interpretations. This collaborative project combines the resources of CU Denver and UC Berkeley to study the lower ionosphere during the solar eclipse of 2024 in the United States, using VLF and ELF remote sensing techniques. Three types of receiver hardware will be used to make synergistic observations during the solar eclipse events. The observations will be interpreted with numerical modeling efforts to answer outstanding questions on the dynamics of the lower ionosphere during an eclipse. The three science questions are 1) What is the lateral and vertical structure of the ionosphere in the totality zone of the solar eclipse? 2) What are the observed ionospheric perturbations when the region of totality is near a powerful VLF transmitter? and 3) What is the lower ionosphere characteristic reaction time to a point like perturbation from the eclipse? The specifics of the 2024 total solar eclipse bring the lunar shadow to the close vicinity of the most powerful VLF transmitter in the United States. This offers a unique opportunity to study a solar eclipse with higher resolution and in the presence of local heating effects. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.