Date: Friday, April 4th, 2025
Time: 1:00 pm CT
Advisor: Dr. Stephen Fuselier

“A Study of Far-Flank Reconnection at Earth’s Magnetopause using MMS ”

Magnetic reconnection is a fundamental plasma process, meaning it occurs in all plasmas. Magnetic recon-nection involves the breaking and re-establishing of magnetic field lines in a plasma, such that mass and energy are transferred between plasmas. Notably, magnetic reconnection is extremely prevalent in the Earth’s magnetosphere making it an ideal laboratory to study this phenomenon. The Magnetospheric Multiscale Mission (MMS) was designed to study exactly that.

There is little discussion of magnetic reconnection on the flanks of the Earth’s magnetosphere. The flanks are regions near or past the terminator (dawn-dusk line) of Earth. I address this problem directly, first by completing a statistical study of far-flank magnetopause crossings. The magnetopause is the boundary between the Earth’s mag-netic sphere of influence, and the Sun’s. In these magnetopause crossings, I looked for signatures of reconnection in both the ions and the electrons. I find that reconnection is prevalent in this region under the right circumstances, de-spite some theory and simulations suggesting otherwise. I also find that there are some differences, such as occasion-al disagreement between ion and electron signatures.

Plasma flows into the reconnection region at a slow rate and gets expelled in two oppositely directed “jets” or beams. The direction of the beam tells us where the spacecraft was with respect to the reconnection x-line. There-fore, the mismatched reconnection signatures found in the first study were of particular note.

To investigate this finding, I completed a study of reconnection events very close to the reconnection site and compare these real-life examples with a simulation. These events are referred to as beam switch events, as you can see the physical reversal of the ion or electron beam. I established basic parameters for these events. From the com-parison to the simulations, I discovered that spacecraft data and more accurate simulations are comparable.