Presentation 1 : Invited
HEATING OF THE SOLAR CORONA: A BRIEF REVIEW (PNST)
Sebastien Galtier & Karine Bocchialini
At the beginning of the third millenium, and after several decades
of research, we are still trying to understand the exact mechanisms
leading to the heating of the solar corona. Many observations (Skylab,
Yohkoh, SoHO, TRACE, etc...) seem however to show that the solar
activity and the coronal heating are related to the solar magnetic
field. This activity is characterized, for example, by a
spatio-temporal intermittent brightness of the corona in the X-ray or
UV domain. Several heating mechanisms of coronal magnetic loop have
been proposed but during the last decade the attention has mostly been
focused on statistical models (phenomenological or turbulent fluid
models) which are able to reproduce the probability distribution
functions observed for solar flares.
In this talk a brief review will be given on observations and heating
models of magnetic loops.
Presentation 2 : Poster
A SOLAR CELLULAR AUTOMATA MODEL ISSUED FROM REDUCED MHD (PNST)
Buchlin E., Aletti V., Galtier S., Velli M., Einaudi G., et Vial J.-C.
A three-dimensional cellular automata model inspired by the reduced
magnetohydrodynamic equations is presented to describe impulsive
events generated along a coronal magnetic loop. It consists of a set
of planes, distributed along the loop, between which the information
propagates through Alfvén waves. Statistical properties in terms of
power laws are obtained in agreement with SoHO observations of X-ray
bright points of the quiet Sun. Physical meaning and limits of the
model are discussed.