4 p.m. - 5 p.m. Location: SLC 2.303
Dr. Lunjin Chen (UT Dallas)
The Earth’s magnetosphere, our geospace environment a few thousand kilometers above the Earth’s surface, consists of energetic charge particles trapped by the Earth’s magnetic field. Those energetic particles exhibit great variability due to solar activities, and pose a great threat to spacecraft orbiting in it and to astronauts. Understanding and predicting their variability are of great interest for space weather. A variety of naturally occurring electromagnetic waves, from Ultra Low Frequency to Very Low Frequency, play important roles in dynamics of those energetic charge particles, especially the radiation belts referring to population of relativistic electrons. The effect of plasma waves on radiation belts is modeled by quasilinear diffusion in the momentum and L-shell, leading to loss, acceleration, and radial transport. In this tutorial talk, I will start with a brief introduction of the Earth’s inner magnetosphere, where three populations of charge particles over different energy ranges, plasmasphere, ring current and radiation belts, coexist. The presentation will then go over basics of wave particle interaction and radiation belt modeling, followed by an overview of plasma waves in the magnetosphere. Finally I will discuss currently active scientific questions in radiation belt physics and ongoing research activities conducted in my research group.