Small-scale Ejections in the Sun’s Photosphere through Chromosphere and Corona

This project studies small-scale ejections in the Sun’s atmosphere, from photosphere through chromosphere to corona, that can have significant influence on the structure and dynamics of the solar corona and solar wind. The goal is to advance our understanding of compelling questions in solar physics, including the interrelationship among various small jet-like phenomena, their linkage to the variable magnetic field of the Sun, and their energy and mass contributions to coronal heating and acceleration of solar wind. The researchers will use high-resolution observations of the Sun from the Goode Solar Telescope (GST) in California and space-based observatories. Data analysis tools improved and/or developed by this project will be made publicly available and will help with science planning and analysis of other ground-based solar observations, especially using the NSF-funded Daniel K. Inouye Solar Telescope. Research results will be incorporated into advanced courses offered by the New Jersey Institute of Technology, which serves a significant number of students from groups underrepresented in STEM.Small-scale jet-like ejections in the solar atmosphere, including chromospheric type II spicules, macrospicules, mini-filament eruptions, and transition region and coronal jets, come in different spatial and temporal scales and magnitude. These events may be associated with small-scale magnetic reconnection, responsible for providing the upward flux of energy and momentum and plausibly driving the small transients in the solar wind. A statistical study of high-resolution photospheric/chromospheric observations from GST combined with multiwavelength spectroscopic observations from the space-based Interface Region Imaging Spectrograph, Solar Dynamics Observatory, and Hinode missions will be performed to derive the key characteristics, including sizes, lifetimes, occurrence rates, velocity, and mass and energy outputs of these small-scale ejections. Observational analysis, using inversion analysis of the differential emission measure and spectroscopic Doppler motion, will advance our understanding of the interrelationship among small-scale ejections in the chromosphere, transition region and corona and their role in the coronal heating and mass loading, and provide physical constraints to jet models. Additionally, the results will shed light on how the associated photospheric magnetic fields evolve prior to ejections and how the physical properties differ between the jet-like ejection events in and outside of coronal holes.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.