Simulational modeling of time-domain magnetic induction using parallel computational schemes: (II) in the spherical coordinates

New parallel codes have been developed to carry out simulational experiments of magnetotelluric investigation in the spherical coordinates by solving the electromagnetic induction equation in the time domain. In our previous paper published in this journal1 we tested the Cartesian code and showed that the code can achieve good performance of parallel processing. The extension to the spherical coordinates is presented here in order to handle the global effect of magnetic induction and while avoiding the restriction and errors caused by the boundary condition in the Cartesian code. We adopt the bi-conjugate gradient stabilized method and the conjugate gradient square method to solve the induction equation. We use the incomplete factorization preconditioner and the Neumann preconditioner for preconditioning. We also compare the performance of these two methods associated with these two preconditioners on three different computers. We also show the effect of vectorization of the code in both of the vector and scalar computers. This spherical code has a promising prospect to carry out global magnetotelluric investigation through computer experiments.  2001 Elsevier Science B.V. All rights reserved. PACS: 91.25.Qi; 91.35.x; 91.60.Pn; 02.70.Bf; 02.60.Jn; 41.20.Bt