WFU Physics Colloquium
Title:
"Auroral Electrons: Measurement and Interpretation"
Speaker:
Dr. James Clemmons
, Goddard Spaceflight Center, NASA, Greenbelt, MD.
Time:
4 PM, Tuesday, April 23, 1996
Place:
Room 101, Olin Physical Laboratory
All interested persons are cordially invited. Refreshments will be
served at 3:30 PM in the lounge.
Abstract
This talk will explore auroral electron acceleration phenomena from an
experimental point of view. After a brief introduction to the aurora
and discussion of early in situ measurements, it will be showin that
several types of auroral electron precipitation are observed. The
focus then narrows to the two types of preciptation important for
discrete auroral arcs: isotropic, "inverted-V" precipitation and
bursts of electrons aligned along the ambient magnetic field.
Observations by the Freja spacecraft are used to illustrate the
properties of both forms of precipitation and the mechanisms commonly
employed to explain their physics are described. High-resolution
measurements from Freja's TESP electron spectrometer are then used
to probe the details of the field-aligned bursts. These measurements
include those from one of the special modes of the instrument designed
to measure fine beam structure. Interpretation of the observations
and the concurrent field measurements allows the development of a
model which unifies the mechanisms for both types of precipitation
into a single paradigm. New ideas for further study of these phenomena
are then put forth.
WFU Physics
Home Page