Upward Frequency Sweeping Due to the Nonlinear Resonance of Multiwave Coupling and Its Significant Contribution to the Hall Effect at the Reconnection Point

We suggest a nonlinear resonance mechanism to explain how the Hall term predominates the convection term at the reconnection point during magnetic reconnection quantitatively. Both the case with guide field and that without guide field are run in this simulation. The new findings are as follows: (1) The Hall term compared to the convection term can reach the order of several tens with sharp peaks at the reconnection point in the former case. (2) The frequency range of electrostatic waves at the reconnection point in the former case is broader than that in the latter case. (3) The instantaneous frequency of x or z component of the Hall term can pulse instantly in the former case, and it can exceed the order of 10 in this case. The upward frequency sweeping due to the nonlinear resonance of multiwave coupling is inferred to be responsible for the above simulation results.