HR: 0800h
AN: SH41A-1118    [Abstracts]
TI: Numerical Simulations of Solar Acoustic Field
AU: * Parchevsky, K V
EM: KParchevsky@solar.stanford.edu
AF: Stanford University, 455 Via Palou, Stanford, CA 94305 United States
AU: Kosovichev, A G
EM: AKosovichev@solar.stanford.edu
AF: Stanford University, 455 Via Palou, Stanford, CA 94305 United States
AB: We present numerical simulations of propagation of acoustic waves in the upper convection zone using a standard solar model and realistic equation of state (OPAL model). The main goals are to study properties of solar waves for various excitation sources and interaction of these waves with spatial inhomogeneities, and also to generate artificial wave fields for testing local helioseismic diagnostics of the solar interior, currently used for SOHO/MDI and GONG data. In our numerical model, non-reflecting boundary conditions based on absorbing 3D perfectly matched layer (PML) are imposed at all boundaries of the computational domain in Cartesian geometry. This prevents spurious reflection of acoustic waves from boundaries back to the computational domain. The top non-reflecting boundary is set in the solar atmosphere above the temperature minimum. This allowed us to realistically model the wave reflection from the solar atmosphere. We have developed a special PLM model, numerically stable in the case of a stratified medium with gravity, and investigated and tested various numerical schemes (including high-order dispersion-relation-preserving scheme). Numerical simulations have been carried out on parallel computers for different kinds of acoustic sources(force and energy sources). Single point sources are used to calculate realistic Green functions required for holographic seismic imaging. Simulated acoustic field from multiple sources randomly distributed below the photosphere is used as artificial data for testing helioseismic inversions, accuracy of Born and ray approximations.
DE: 7522 Helioseismology
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005