ECE graduate student awarded NASA FINESST Fellowship

8/1/2021

Raluca Ilie, Illinois ECE

Mei-Yun Lin
Mei-Yun Lin

Illinois ECE graduate student Mei-Yun Lin was recently awarded the Future Investigators in NASA Earth and Space Science and Technology (FINESST) Fellowship for her proposal entitled "The Curious Case of Heavy Ions and Their Journey Through Space." The FINESST Fellowship provides research grants to graduate students who are designing and performing research projects relevant to the interests of the NASA Science Mission Directorate (SMD) in one or more of four divisions: Earth Sciences, Heliophysics, Planetary Science, and Astrophysics. 

Advised by ECE Assistant Professor Raluca Ilie, Lin proposes to quantify the role of the heavy ions in the Earth’s ionosphere-magnetosphere system with further development of the polar wind model. Atomic N+, O+, and molecular N2+, NO+, and O2+ ions, are often thought to be gravitationally bounded, and only populate the Earth's lower atmosphere. Molecular ions are expected to undergo recombination reactions to form a pair of neutral atoms, due to the short dissociative recombination lifetime.

Raluca Ilie
Raluca Ilie

Therefore, they are required to obtain the additional energy on a short time-scale to escape from the Earth's ionosphere. Although past observations show the importance of the heavy ions in the high-altitude ionosphere and magnetosphere, the mechanisms responsible for accelerating the ionospheric heavy ions from eV to keV energies are still largely unknown. In the proposal, Lin and Ilie seek to solve for the production and transport of all relevant heavy ions species (N+, O+, N2+, NO+, and O2+) in the Earth's polar wind region and provide answers to the following questions:

1. What are the competing mechanisms to produce and transport all ionospheric heavy ions, including the molecular species, along open magnetic field lines?

2. How does the three-dimensional spatial distribution of heavy ions outflow, including molecular species, change during the geomagnetically active times?

This project combines advanced numerical tools to systematically examine the effect of season, solar activity, and wave heating on the evolution and structure of ionospheric outflow, by tracking the vertical transport of all relevant ion species along open magnetic field lines, as well as the horizontal transport across the polar cap as driven by solar wind conditions. Lin and Ilie will further develop the Seven ion Polar Wind Outflow Model (7iPWOM) to track the behavior of all major ionospheric species in the polar wind, from low altitude ionosphere to several Earth radii.

The 7iPWOM will be the first and only polar wind model to have the capability to study the behavior of the heavy ions, other than O+, in the Earth’s ionospheric outflow. The work can augment the knowledge of the plasma transport processes from the ionosphere to the magnetosphere, and help interpret the observations of the heavy ions, including molecular species, in the ionosphere-magnetosphere system from various missions, such as Arase satellite and ARTEMIS spacecraft.

This proposal will enhance, complement, and augment the scientific yield from operating Heliophysics missions while guiding the development of new instrumentation and space missions, which is highly relevant to NASA's Heliophysics Program. The proposed study also has the potential to explain the changes in exospheric morphology and could lead to a better understanding of planetary atmospheric evolution based on the knowledge of the history of the Earth, which is aligned with the Planetary Research Program. 

For more information on this year's FINESST recipients, click here.