On nonreflecting projective characteristic boundary con-dition and its application in the numerical simulation of as-ymmetric coronal structures

The conventional nonreflecting projective charac teristic boundary condition for MHD equations is improved in order to remove spurious oscillations caused by the presence of zero point of the components of magnetic field. The improved boundary condition is easier to be implemented in programming, and its application to the simulation of asymmetric corona can give us stable coronal static structures.