Collaborative Research: Understanding the Quiet Time Thermospheric Composition Contribution to Ionospheric Day-to-Day Variability over the American Continent

The ionosphere and thermosphere exhibit significant day-to-day variability even during quiet times. Understanding these background variations and their interrelationships is essential for effective space weather forecasting. This project aims to characterize how these quiet-time variabilities impact one another, a key factor in determining the responses of the ionosphere and thermosphere to geomagnetic storms. This research not only supports advancements in space weather prediction but also includes educational outreach activities to engage physics students and the public in space physics, fostering interests in STEM fields. Additionally, the project will provide hands-on training for a graduate student, enhancing his/her academic development in space physics research. This project aims to investigate the correlation between quiet time ionosphere day-to-day variability and quiet time thermosphere composition day-to-day variability. Through utilizing ground-based Global Navigation Satellite System (GNSS) observations, NASA's Global-scale Observations of Limb and Disk (GOLD) mission, and Whole Atmosphere Community Climate Model eXtended (WACCM-X) simulations, this study involves identifying geomagnetically quiet periods and analyzing ground-based and satellite observations to characterize the two-dimensional patterns of ionospheric total electron content (TEC) and thermospheric column density ratio of atomic oxygen to molecular nitrogen (O/N2) day-to-day variability. Statistical analyses will be conducted to examine the spatial and temporal distributions of quiet time TEC and O/N2 day-to-day variability. Additionally, WACCM-X simulations will be performed to investigate the underlying mechanisms and assess the role of O/N2 day-to-day variability in TEC day-to-day variability through data-model comparisons and diagnostic analyses. This research endeavors to unravel the complexities of quiet time thermosphere and ionosphere day-to-day variability. The resulting database of quiet time TEC day-to-day variability and O/N2 day-to-day variability, as well as the numerical simulation results, will be a reference for the Aeronomy community to carry out related research. 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.