2022 Thayer Investiture

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Engineering-Physics Space Plasma Seminar

Apr

20

Tuesday
4:00pm - 5:00pm EST

Videoconference

Zoom: Email tressena.a.manning@dartmouth.edu for link and password.

"Magnetic Entanglement"

Magnetic entanglement is a phenomenon that happens when magnetic field lines of different connectivity encounter and pull against each other. It is ubiquitous in space plasma and one of the places that we can find it is on the Earth’s magnetopause where Flux Transfer Events (FTEs), as flux ropes (FRs), take place and work as key agents for solar wind energy to enter the terrestrial magnetosphere. Recent observations by the Magnetospheric Multiscale (MMS) mission have identified entangled flux tubes that collide and pull against each other. Reconnection occurs to disentangle and produce a new pair of flux ropes with different connectivity. We examine the entanglement interface and how such entanglement process evolves in time by comparing 17 entanglements observed by MMS and identify three evolutionary stages characterized by the magnetic field and pressure enhancement. To better understand the transport of particles and energy between the magnetosphere and the solar wind, we use a three‐dimensional Hall Magnetohydrodynamics (MHD) model to simulate the interaction of two entangled flux tubes in the ambient plasma. Four types of interactions are simulated: Two types of magnetic field geometry (flux tube‐flux tube and flux rope‐flux rope) are tested separately, each under two different boundary conditions. The results supports the feasibility of reconnection between entangled flux tubes, and quantifies how such structures evolve to modify the solar wind‐geomagnetic field interaction. Moreover, we have found that magnetic entanglement has been identified in flux tube interactions beyond the earth, such as in the solar corona and solar wind.

About the Speaker(s)

Yi Qi
UCLA

Contact

For more information, contact Tressena Manning at tressena.a.manning@dartmouth.edu or +1 (603) 646-2854.