Numerical simulation of internal plasma dynamics of post-flare loops

FERÁNDEZ, CARLOS; COSTA, ANDREA; ELASKAR, SERGIO; MARTÍNEZ, GUADALUPE.; ROVIRA, MARTA

Rio de Janiero

Simposio; Solar and Stellar Variability - Impact on the Earth and Planets; 2009

We integrate the MHD ideal equations of a slender flux tube to simulate the internal plasma dynamics of coronal post-flare loops. We study the onset and evolution of the internalplasma instability to compare with observations. The numerical approach uses a finite-volume Harten-Yee TVD scheme to integrate the 1D 1/2 MHD equations specially designed to capture supersonic flow discontinuities. We show that high-speed downflow perturbations, usually interpreted as slow magnetoacoustic waves, could be better interpreted as slow magnetoacoustic shock waves. A time-dependent forcing from the basis is needed to reproduce the reiteration of the event which resembles observational patterns ?commonly known as quasi-periodic pulsations (QPPs)? which are related with large scale characteristic longitudes of coherence. This result reinforces the interpretation that the QPPs are response to the pulsational flaring activity.