ECE PhD student Hsinju Chen has received the prestigious NASA FINESST (Future Investigators in NASA Earth and Space Science and Technology) award to study the mechanisms that control the transport and loss of nitrogen ions and oxygen ions and understand their different pathways. Tracking the loss of nitrogen ions could provide clues about a planet's ability to sustain life, as the temperate climate conditions on the Earth's surface are facilitated by its nitrogen-dominated atmosphere.
Written by Eleanor Wyllie
On Earth, habitable conditions can be influenced by variations in atmospheric oxygen levels and the intensity of the Earth’s magnetic field. Oxygen, and other heavy species in the atmosphere, can escape into interplanetary space as ions after gaining sufficient energy to overcome Earth’s gravitational pull. While many observations have shown that heavy ions — nitrogen ions and oxygen ions — flow out from the high-latitude atmosphere into outer space, limited efforts have been made to analyze the impact and pathways of N+ and O+ as separate species in the near-Earth environment. Tracking the loss of nitrogen ions could provide clues about a planet's ability to sustain life, as the temperate climate conditions on the Earth's surface are facilitated by its nitrogen-dominated atmosphere.
Hsinju Chen, PhD student at ECE
ECE PhD student Hsinju Chen has received the prestigious NASA FINESST (Future Investigators in NASA Earth and Space Science and Technology) award to study the mechanisms that control the transport and loss of N+ in addition to that of O+ and understand their differential transport. This new knowledge will provide insights into whether an atmosphere is thick enough to stabilize liquid water on a planet's surface, which is fundamental to creating habitable conditions. This work will contextualize existing spacecraft observation data, help future mission design, and advance our understanding of habitability conditions and space weather.
“For decades, studies grouped nitrogen and oxygen ions together due to their similar masses, primarily because it is technologically challenging for mass spectrometers on board spacecraft to tell them apart,” Chen says. “But they have many different chemical properties and obey vastly different physical processes. We don’t know how these species are being locally energized and accelerated, nor their pathways to escape the terrestrial environment.”
Chen aims to understand this differential transport of heavy elements as they are eroded from the Earth’s atmosphere. The FINESST award provides three years of funding and supercomputing resources for this project. Chen utilizes state-of-the-art high-performance numerical modeling techniques, and their model is the first multi-fluid magnetohydrodynamic model that includes nitrogen ions in the global simulation space.
Chen is the second student in Professor Raluca Ilie’s Heliophysics Research and Applications (HeRA) group to receive the NASA FINESST award.
“Hsinju is growing into the type of scientist who can creatively bring new twists on old ideas to stimulate new solutions to scientific problems,” Ilie said. “Their work has created a paradigm shift in the way we understand the transport of heavy elements from the high latitude atmosphere to outer space, and this project can potentially resolve long-standing questions about the impacts of planetary magnetism on habitability. But their determination, outstanding work ethic, and deliberately inclusive communication style also contributed to the success of this proposal. I can’t think of anyone more deserving of this award.”
This shows the transport of the ions (H+: yellow-green, N+: orange, O+: blue), the geomagnetic field (black arrow lines), and the total ion number density (color contour) over the course of a 12-hour storm (September 2017). The center gray sphere is the inner boundary of the simulation (radius = 2.5 Earth radii). Created by Hsinju Chen.