How the resistivity acts near a coronal null point

We investigate the effect of magnetic resistivity on the propagation and evolution of magnetoacoustic waves and plasma in the neighborhood of a magnetic null-point. Various values for the magnetic resistivity associated with solar coronal conditions have been taken under consideration in the context of magnetohydrodynamics by implementing the PLUTO code. The magnetic diffusivity controls the current sheet and spikes together with their direction. The same goes for the direction of the induced flows as the speed of the induced flows is proportional with the magnetic diffusivity. This is while the acceleration of the flows is inversely proportional with the magnetic diffusivity. The high values of magnetic diffusivity contribute towards the collapse of magnetic fields while reversing the direction of the induced flows. Therefore, null collapse is a class of MHD implosion that null is the center of converging magnetic flux and plasma compression and refraction happen due to the converging and diverging flow driven by Lorentz force. The implosion continues until some limiting events can develop sufficiently to stop this focusing. The current density at the magnetic null-point is dependent on the magnetic diffusivity that could be related to the high gradient of the magnetic field around the null point. A relatively high value of the magnetic diffusivity causes the current density to possess a positive value while it possesses a negative value for relatively low values. The opposite value for the polarity of the current density is associated with the opposite direction of the magnetic null-point collapse. Besides, it is found that at initial timescales prior to the creation of plasmoids, the plasma density is small with high current density accumulation at small magnetic diffusivity values which is in accordance with previous analytic results. But, throughout the entire simulation time the plasma density becomes significant in a sense that the current density would be proportional to the magnetic diffusivity.