Multi-Periodicity of High-Frequency Type III Bursts as a Signature of the Fragmented Magnetic Reconnection

Abstract

Using the radio spectra of the 2 April 2022 eruptive flare, we analyze a group of highfrequency type III bursts by our new wavelet method. In this analysis, we found a multi-periodicity of these bursts that is interpreted by the electron beams accelerated in the fragmented magnetic reconnection in the rising magnetic rope. We propose that each period in these type III bursts is a result of the periodic interaction of sub-ropes formed in the rising magnetic rope. In each interaction, the period depends on the diameter of interacting sub-ropes and local Alfvén velocity. This interpretation is supported by detection of the specific EUV structure which was, according to our knowledge, observed for the first time. All proposed processes occur in the rising magnetic rope. Thus, this flare deviates from the standard flare model, where the main magnetic reconnection is located below the rising magnetic rope.