PROPAGATION OF DISTURBANCES IN THE SOLAR CHROMOSPHERE-CORONA （Ⅱ）

In the first part of this article, the linear properties of MHD wave propagation is discussed. Then, in order to simulate the global characteristics of wave propagation in the solar chromosphere-corona, by employing a 2-dimensional time-dependent compressible MHD simulation subject to a self-consistent non-isothermal, non-uniform initial state, we study numerically the global propagation process of the disturbances initiated by a pressure pulse implemented at the bottom of chromosphere. Numerical results indicate that, in polar region, propagating disturbances can be distinguished into two modes, i.e. fast and slow magneto-acoustic waves. Whereas in the vicinity of solar equator, propagating disturbance is regarded as fast mode wave, and a standing disturbance is found to be located near the source region. These results may help explaining the wave events observed by SOHO/EIT.