SLiM: a code for the simulation of wave propagation through an inhomogeneous, magnetised solar atmosphere

Abstract

In this paper we describe the semi-spectral linear MHD (SLiM) code which we have written to follow the interaction of linear waves through an inhomogeneous three-dimensional solar atmosphere. The background model allows almost arbitrary perturbations of density, temperature, sound speed as well as magnetic and velocity fields. We give details of several of the tests we have used to check the code. The code will be useful in understanding the helioseismic signatures of various solar features, including sunspots.

Modeling the Subsurface Structure of Sunspots

“…A limitation of the direct simulation approach is that it is extremely computationally intensive. The examples shown in Section 7.8 demonstrate that numerical simulations are capable of reproducing many features of the helioseismic measurements (see also Cameron, Gizon, and Duvall, 2008). In addition, simulations promise to provide a powerful tool for determining the sensitivity of helioseismic measurements to small changes in the subsurface structure of sunspot models.…”

“…A number of groups are working on this problem (Khomenko and Collados, 2006;Cameron, Gizon, and Daiffallah, 2007;Parchevsky and Kosovichev, 2007;Hanasoge, 2008;Shelyag et al, 2009). The numerical techniques, and validation and verification procedures vary significantly from one code to another.…”

“…Braun and Birch, 2008;Birch et al, 2009;Gizon et al, 2009aGizon et al, , 2009b) and significant advances have also been made in the simulation of helioseismic wave propagation in magnetized plasmas (see e.g. Cameron, Gizon, and Daiffallah, 2007;Parchevsky and Kosovichev, 2007;Cameron, Gizon, and Duvall, 2008;Hanasoge, 2008;Moradi, Hanasoge, and Cally, 2009;Parchevsky and Kosovichev, 2009;Shelyag et al, 2009;Cameron et al, 2010).…”

“…• Cameron, Gizon, and Duvall (2008), Hanasoge (2008), Shelyag et al (2009): All employed simple self-similar toy sunspot models in conducting numerical simulations of helioseismic wave propagation through magnetized plasmas.…”

“…Cameron, Gizon, and Daiffallah, 2007;Cameron, Gizon, and Duvall, 2008;Moradi, Hanasoge, and Cally, 2009). This approach bypasses the need for linear forward models (i.e.…”