Dartmouth Events

Physics & Astronomy Seminar - Dr. Xin An, UCLA

Title: "Plasma kinetics in the Earth’s magnetosphere"

Thursday, February 22, 2024
2:00pm – 3:00pm
Steele 006 and Zoom
Intended Audience(s): Public
Categories: Arts and Sciences, Lectures & Seminars

Abstract: The stability of the magnetotail current sheet configuration controls the substorm onset, one of the most powerful phenomena in the Earth's magnetosphere. During substorms, energy stored in the magnetotail current sheet is converted to fast plasma flows moving earthward and tailward. As fast plasma flows penetrate to the inner magnetosphere, electromagnetic waves and nonlinear solitary structures in a wide range of spatial-temporal scales are excited by the injected energetic ions and electrons. These waves and structures in turn control particle acceleration and precipitation across a wide energy range in the inner magnetosphere. In this seminar, I will first present the formation of thin current sheets in the magnetotail, from the perspectives of both equatorial and low Earth orbit spacecraft measurements. I will show that how these thin current sheets maintain their kinetic equilibria, both in the near-Earth and lunar-distance magnetotail. I will then discuss the various wave modes generated after such current sheet reconnection and fast plasma flow formation. I will demonstrate how these waves provide the energy cascade from meso-scales (>1000 km) to micro-scales (<1 km) in the fast plasma flows. Finally, I will discuss the long term vision on the incorporation of kinetic wave-particle interactions into current sheets, magnetosphere-ionosphere coupling, and radiation belt modeling.

Hosted by Professor Yi-Hsin Liu

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Meeting ID: 949 6610 1884
Email physics.department@dartmouth.edu for passcode

For more information, contact:
Tressena Manning

Events are free and open to the public unless otherwise noted.