Current sheets formed by Alfven and magnetosonic pulses in the vicinity ofthe null line of the magnetic field

A study is made of the propagation of an Alfven pulse and the superposition of an Alfven and a magnetosonic pulse in the vicinity of the magnetic null line (the X point). It is shown that, on long time scales, the poloidal co mponents of the velocity and magnetic field relax to steady-state distribut ions similar to those in the case of a magnetosonic pulse. In the essential ly nonlinear problem under investigation, the steady-state distributions of the toroidal components of the velocity and magnetic field are found to be close to those in the corresponding linear problem. It is established that two-dimensional effects play an important role in the evolution of the for ming current sheets. (C) 2001 MAIK "Nauka/Interperiodica".