Energy of Alfvén waves generated during magnetic reconnection

A new method for the determination of the Alfvén wave energy generated during magnetic reconnection is introduced and used to analyze the results from two-dimensional MHD simulations. It is found that the regions with strong Alfvén wave perturbations almost coincide with that where both magnetic-field lines and flow-stream lines are bent, suggesting that this method is reliable for identifying Alfvén waves. The magnetic energy during magnetic reconnection is mainly transformed into the thermal energy. The conversion rate to Alfvén wave energy from the magnetic energy is strongly correlated to the magnetic reconnection rate. The maximum conversion rate at the time with the peak reconnection rate is found to be only about 4% for the cases with the plasma beta β=0.01,0.1,and1.0.