Talk abstract

Magneto-Acoustic Waves in Sunspots: First Resuls from New 3D Nonlinear Magnetohydrodynamic Code
Tobías Felipe, Elena Khomenko, Manuel Collados


We have developed a numerical magnetohydrodinamic code for the calculation of the response of a equilibrium magnetic atmosphere to an arbitrary perturbation. The code solves the 3D nonlinear MHD equations for perturbations, which are obtained by subtracting the equations of initial magnetohydrostatic equilibrium from the system of MHD equations. Spatial derivatives are discretized using fourth-order centered differences and the solution is advanced in time using a fourth-order Runge-Kutta scheme. It is stabilized by artificial diffusion terms and its parallelized design is based on a domain decomposition scheme. Several tests are shown to prove the robustness of the code. We also present the results of several simulations of a sunspot perturbed by pulses of different periods at photospheric level, from short periods, introduced for academic purposes, to longer and realistic periods of three and five minutes.