EIT waves are often observed to be propagating EUV enhancements followed by an expanding dimming region after the launch of CMEs. It was widely assumed that they are the coronal counterparts of the chromospheric Moreton waves, though the former are three or more times slower. The existence of a stationary "EIT wave" front in some events, however, posed a big challenge to the wave xplanation. Simulations are performed to reproduce the stationary "EIT wave" front, which is exactly located near the footpoint of the magnetic separatrix, consistent with observations. The formation of the stationary front is discussed in the framework of our model where "EIT waves" are supposed to be generated by successive opening of the field lines covering the erupting flux rope in CMEs.

Magnetohydrodynamic (MHD) equations are numerically solved to study 2.5-dimensional magnetic reconnection with field-aligned heat conduction, which is also compared with the adiabatic case. The dynamical evolution starts after anomalous resistivity is introduced into a hydrostatic solar atmosphere with a force-free current sheet, which might be similar to the configuration before some solar flares. The results show that two jets (i.e., the outflows of the reconnection region) appear. The downward jet col-lides with the closed line-tied

A class of pseudo-reconnection caused by a shifted mesh in MHD simulations is reported. In term of this mesh system, some non-physical results may be obtained in certain circumstances, e.g., magnetic reconnection occurs without resistivity. After comparison, another kind of mesh system is strongly recommended.

The effect of heat conduction on 2.5D magnetic reconnection, similar to that in Kopp-Pneuman model, is numerically studied. It is shown that the heat conduction accelerates the reconnection, increases the amount of shrinkage of the closed field lines, and increases the average rise speed of the SXR loop. MHD slow shocks contribute to the SXR loop heating. When the timescale of heat conduction is shorter than the Alfv

We performed 2.5-dimensional numerical simulations of magnetic reconnection for several models, some with the reconnection point at a high altitude (the X-type point in magnetic reconnection), and one with the reconnection point at a low altitude. In the high-altitude cases, the bright loop appears to rise for a long time, with its two footpoints separating and the field lines below the bright loop shrinking, which are all typical features of two-ribbon flares. The rise speed of the loop and the separation speed of its footpoints depend strongly on the magnetic field B0, to a medium extent on the density P0, and weakly on the temperature To, the resistivity η, and the length scale L0, by which the size of current sheet and the height of the X-point are both scaled. The strong B0 dependence means that the Lorentz force is the dominant factor; the inertia of the plasma may account for the moderate P0 dependence; and the weak η dependence may imply that "fast reconnection" occurs; the weak L0 dependence implies that the flaring loop motion has geometrical self-similarity. In the low-altitude case, the bright loops cease rising only a short time after the impulsive phase of the reconnection and then become rather stable, which shows a distinct similarity to the compact flares. The results imply that the two types of solar flares, i.e., the two-ribbon flares and the compact ones, might be unified into the same magnetic reconnection model, where the height of the reconnection point leads to the bifurcation.