[IGPP Everyone] Space Physics Seminar-Spring Quarter 2018-Friday 5/4/18- 3:30pm Geology 6704

[Marjorie Sowmendran]

SPACE PHYSICS SEMINAR

DEPARTMENT OF EARTH, PLANETARY, AND SPACE SCIENCES

DEPARTMENT OF ATMOSPHERIC AND OCEANIC SCIENCES

UNIVERSITY OF CALIFORNIA, LOS ANGELES

(AOS M275C, EPSS M288C)





Whistler Mode Waves Modulation of Langmuir Waves in the Radiation Belts and Magnetopause



Jinxing Li

Department of Atmospheric & Oceanic Sciences
University of California, Los Angeles



Abstract

Using high-resolution waveforms measured by the Van Allen Probes and MMS spacecraft, we report a novel observation that occurs both in the radiation belts and the dayside magnetopause. Namely, whistler mode waves modulate electrostatic Langmuir wave bursts. In the radiation belts, the modulation of these two wave modes occur over two time scales: rising-tone time scale and chorus phase period time scale. At the magnetopause region, the modulation occurs on whistler mode phase period time scale. The periodic Langmuir wave bursts are generally observed at the phase location where the whistler mode wave E|| component is oriented opposite to its propagation direction. The electron phase space density measurements show a beam at the velocity that matches the parallel phase velocity of the whistler mode waves. Based on this evidence, we conclude that the whistler mode waves accelerate the suprathermal electrons via Landau resonance, and generate a localized periodic electron beam in phase space density. The Langmuir waves are subsequently excited and modulated by the whistler mode wave phase. This microscale interaction provides a new insight into the nonlinear wave-particle interaction and the energy conversion processes occurred both in the radiation belts and in the reconnection regions.

 Friday, May 4, 2018

Room 6704 Geology

3:30 - 5:00 PM

In-Charge: C. T. Russell 

Presiding: Yingjuan Ma
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