Barbara Thompson's 1995 AGU Spring Meeting Poster

Electron Acceleration by Inertial Alfven Waves:

by Barbara Thompson and R. L. Lysak

Welcome to the poster presentation. (Web readers: Some of the figures originally included in the poster are not yet available in this version). The purpose of this addition to the poster is to provide the reader with background about inertial Alfven waves and their potential role in auroral acceleration processes. While the poster focuses on more recent results, details and derivations have been omitted to conserve space. Unfortunately, equations are not legible in formats which are readily accessible, so the descriptions and derivations will be more heuristic and less rigorous.

If you are more interested in physical results than nonlinear dynamics and chaos, you may want to go straight to the "Real Systems and Physical Relevance" section of the poster.

Any word which is highlighted and underlined (for example, the list of sections) serves as a link to more information on the subject. Moving the cursor to the word and clicking on it opens an additional page - you can return to this page by either clicking "home" above or by pressing "back."


A numerical model calculating the propagation of inertial Alfven waves has been developed. The system consists of a realistic physical environment represented numerically by equations for magnetic field, density, Alfven speed, conductivity, and other physical parameters.

The wave includes the effect of electron inertia through the Generalized Ohm's law. The system is treated as a wave in a dielectric medium and is integrated in time as it propagates along auroral field lines.

The inertial term allows the existence of a finite electric field parallel to the background geomagnetic field. This field is calculated in the simulation, and is used to accelerate electrons with a method which conserves energy. The simulation electrons, which can reach energies of several keV, result in distributions similar to observed behavior.

Although the collective behavior of the Alfven wave and the electron distributions produce observable results in the model, Individual electron orbits can display distinctly chaotic behavior. These interactions add several degrees of complexity to the system.


Alfven waves and auroral systems - simple overview

System properties and physical behavior

Deriving the wave equations including electron inertial effects

Dielectric treatment of Alfven waves

Wave integration - fluid motion

Electron integration - particle motion

Electron effects and commonly observed distributions

Conserving energy - numerical scheme

Chaotic behavior of system

References - please see poster

Thank you

If we had an internet connection, I'd have a place here where you could leave messages and email with comments and suggestions. As this is not the case, I conclude by thanking you for your interest and wishing you a pleasant meeting.

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