Examining the Thermospheric Tidal Variability and its Impact on Ionospheric Variability using Whole Atmosphere Modeling and Observations

About This Grant

The overarching goal of this project is to investigate the sources of day-to-day variability in near- Earth space environment during geomagnetically quiet periods. Forecasting of space weather is often done using physics-based computer models. However, these models often lack skills in accurately predicting day-to-day variabilities, a significant portion of which originates from the lower atmosphere. This project aims to improve the scientific understanding of these variabilities using state-of the-art Whole atmosphere Model-Ionosphere Plasmasphere Electrodynamics (WAM-IPE). The improvements of the model, and scientific insights gained from this project have the potential to directly enhance the forecasting accuracy of the operational version of WAM-IPE at NOAA’s Space Weather Prediction Center (SWPC), which monitors and provides regular space weather alerts to a wide range of stakeholders. The model improvements and scientific tools developed in this project will be made publicly available, fostering collaboration across the scientific community. In addition, the project will provide training opportunities for early career scientists enabling development of a broad and skilled workforce prepared to address future challenges of our society in short-term predictive space weather science. This project aims to advance understanding of the connections between day-to- day variability in the ionosphere, ionospheric electrodynamics and neutral wind tides in the Ionosphere- (I-T) region. The neutral wind in the lower thermosphere ~90-150km region is highly variable due to complex spectra of upward propagating waves from the lower atmosphere. Numerical whole atmosphere models have been increasingly used in the investigations of fundamental I-T processes for accurate space weather forecasting. However, these models have a major source of uncertainty stemming from poor understanding of drivers of short-term variability. To address this uncertainty, the proposal will leverage state-of-the art Whole atmosphere Model- Ionosphere Plasmasphere Electrodynamics (WAM-IPE) model in conjunction with diverse observations from ground- and space-based instruments. Specifically, this study will focus on quantifying the contributions of different tidal components to the variability of the upper mesosphere, middle thermosphere to bottom side F-regions of the Earth’s atmosphere (~80-250 km). Advanced techniques such as autocorrelation and wavelet coherence analysis will be used. Ultimately, by revealing causal mechanisms linking tidal day-to-day variability to ionospheric changes, this research will play a significant role in enhancing I-T predictability during geomagnetically quiet times, driving future advancements in whole atmosphere modeling, improving operational forecasts at NOAA/SWPC, and strengthening global space weather resilience. 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.