SIMULATIONS OF NONSTATIONARY MAGNETIC RECONNECTION IN LIE-TRANSPORTEDELECTROMAGNETIC-FIELDS

Magnetic reconnection is simulated with the help of covariant transpor t equations for the electro-magnetic held They include an induction eq uation for the magnetic as well as the electric held The transporting dow is a four-vector field (W-4). The space components of this four-ve ctor held an of stagnation flow type and the time-component vanishes a t the reconnection site. The numerical method and necessary special nu merical treatment at the line along which reconnection occurs is descr ibed in detail The way in which the time-component (W-0) of the transp orting flow approaches zero at the reconnection line controls the type of non-ideal dynamics. Different profiles resulting in various curren t density distributions are studied In reality the non-idealness neces sary for reconnection may result from current-dependent micro-instabil ities and therefore a current-dependent profile of W-0 is included.