Collaborative Research: Exploring Polar Ionospheric Precipitation Using Antarctic X-ray Observations

Energetic particles constantly rain down from near-Earth space into the upper atmosphere, where they can disrupt communications, degrade satellite systems, and alter atmospheric chemistry that influences climate. This project will investigate how and why these particles, especially high-energy electrons, are lost from Earth’s magnetic environment and precipitate into the atmosphere. By improving understanding of these processes, the research will help scientists better predict space weather, which is critical for protecting satellites, GPS navigation, aviation operations, and power grids. The project will also advance the use of innovative measurement techniques, including balloon experiments and small satellites, to observe space from multiple vantage points. In addition to its scientific contributions, the work will support the training of students and early-career researchers in cutting-edge space science and data analysis methods, helping to build a skilled workforce in science and engineering. Public outreach and open data efforts will further ensure that the benefits of this research extend beyond the scientific community. This project focuses on quantifying energetic electron precipitation (EEP) from the outer radiation belt and near-Earth plasma sheet, with emphasis on three key mechanisms: whistler-mode wave scattering, electromagnetic ion cyclotron (EMIC) wave interactions, and field-line curvature scattering (FLCS). The research addresses fundamental gaps in understanding the spatial and temporal variability of EEP, particularly the limitations of single-point low-altitude observations in resolving rapidly evolving precipitation structures. The project will integrate complementary datasets, including low-altitude satellite measurements (e.g., ELFIN, POES), long-duration balloon-borne X-ray observations (BARREL), and supporting measurements from near-equatorial spacecraft and ground-based instruments. The study will combine statistical analysis of multi-instrument observations with event-based investigations to characterize precipitation spectra, pitch-angle distributions, and temporal evolution. Special attention will be given to identifying signatures of microbursts and EMIC-driven precipitation in X-ray data, as well as diagnosing FLCS through isotropy boundary observations and their energy–latitude dispersion. Cross-comparison across datasets will enable reconstruction of precipitation dynamics over multiple scales. The project will also incorporate modeling frameworks to relate observed precipitation to underlying wave-particle interactions and magnetic field geometry. The expected outcome is a unified, quantitative description of EEP drivers and their relative contributions, improving predictive capability for radiation belt dynamics and space weather impacts. 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.