AAS Meeting #194 - Chicago, Illinois, May/June 1999
Session 23. Microflares and Coronal Heating
Oral, Monday, May 31, 1999, 10:00-11:30am, Continental Ballroom C

[Previous] | [Session 23] | [Next]

[23.05] Energetics of Transition Region Dynamics Observed by SUMER on SOHO

A. R. Winebarger (Univ. of AL in Huntsville)

The plasma constituting the solar transition region exhibits a variety of motions, including directed flows, non-thermal mass motions (or microturbulence) and, in the most extreme cases, highly skewed or extremely broadened velocity distributions. These extreme motions result in shifted, broadened, and skewed spectral lines commonly referred to as explosive events. Using high spectral, spatial, and temporal resolution SUMER data of various transition region lines, we have developed new criteria to define explosive events and present a summary of explosive event characteristics, such as birthrate, average lifetime, and average energy. We have also employed a new method of deriving the energy flux associated with explosive event line profiles. Our results show that previous measurements of energy flux, estimated from characteristic velocities of the plasma, are an order of magnitude, or more, too low. Using the more correct measure of energy flux, we have, for the first time, developed the energy distribution (dN/dE) of explosive events, taking into account projection effects. We will compare the energy distribution of event profiles to ``normal'' non-event profiles and discuss the implications on solar coronal heating, nanoflares, and explosive event theory.

If the author provided an email address or URL for general inquiries, it is a s follows:

[Previous] | [Session 23] | [Next]