Multiplatform Investigation of the Role of Wave Accelerated Electrons in
Magnetospheric Processes

S. Mende, H. Frey, C. Carlson, and L. Peticolas


Intense fluxes of wave accelerated low energy electrons in auroras signify the
location of large scale energy input from the magnetosphere. Studying these wave
accelerated electron (WAE) auroras require the monitoring of the auroral
dynamics by high resolution (ground- or space-based) imaging while
simultaneously measuring the particles at various altitudes to determine the
characteristic electron spectrum and to observe the transition of wave Poynting
flux into electron energy. This wave acceleration is another distinct and
presumably transient process by which magnetic energy of the magnetosphere is
converted into particle (electron) energy and transmitted into the atmosphere in
the form of auroral electrons. Using the FAST satellite and auroral imaging from
the IMAGE spacecraft we were able to show that prior to substorm onset WAE
auroras occur infrequently and mostly near the poleward boundary of the auroral
oval, presumably near the boundary of open and closed field  lines, where steady
state reconnection is expected to occur. At onset WAE electrons play a primary
role in the surge formation and the break up aurora. This aurora is located deep
in the region of closed field lines. After onset the poleward propagating
auroral surge consists of WAE electrons at the poleward edge of the closed field
configuration and is closely followed by inverted V type precipitation. The
ground based auroral imaging operating simultaneously with the future THEMIS
satellites will have better spatial resolution for the investigation of the
aurora associated with these processes.

_______________ 
Presentation, Fall A.G.U. Meeting, San Francisco, CA, 13-17 December 2004