Numerical simulations of slow magnetosonic standing waves in a straight solar coronal slab

¹ Department of Computer Sciences, The State University in Chełm, ul. Pocztowa 54, 22-100 Chełm, Poland e-mail: rogrodow@pwsz.chelm.pl
² Group of Astrophysics and Gravity Theory, UMCS, ul. Radziszewskiego 10, 20-031 Lublin, Poland

Received: 19 January 2007
Accepted: 25 January 2007

Abstract

Aims.We consider a simple model of a straight solar coronal slab to explore excitation and attenuation of impulsively triggered slow magnetosonic standing waves.

Methods.The full set of ideal magnetohydrodynamic equations is solved numerically in the limit of a two-dimensional approximation.

Results.The numerical results reveal that pulses, launched initially in gas pressure, trigger the fundamental slow mode and its first harmonic, depending on the spatial location of these pulses. These modes are excited over 3-5 wave periods and they are strongly attenuated over a similar time-scale.

Conclusions.As a result of the transition of the initial pulse to the modal structure through energy transfer into the ambient solar corona and into the photospheric regions, as well as of coupling with fast magnetosonic waves that spread energy over the whole physical system, these slow modes are excited faster and they are attenuated more efficiently than in the one-dimensional case.