Preliminary Discussion on the Current Sheet

Abstract

The current sheet is a characteristic structure of magnetic energy dissipation during the magnetic reconnection process. So far, the width and depth of the current sheet are still indefinite. Here we investigate 64 current sheets observed by four telescopes from 1999 to 2022, and all of them have been well identified in the previous literature. In each current sheet, three width values are obtained at the quartering points. Based on these investigated cases, we obtain 192 values, which are in a wide range from hundreds to tens of thousands of kilometers. By calculating the pixel width (PW: the ratio of the current sheet width to the pixel resolution of corresponding observed data) of these current sheets, we find that more than 80% of the PW values concentrate on 2–4 pixels, indicating that the widths of the current sheets are dependent strongly on the instrument resolutions and all the sheets have no observable three-dimensional information. To interpret this result, we suggest that there are two probabilities. One is that the width of the current sheet is smaller than the instrument resolution, and the other is that the detected current sheet is only a small segment of the real one. Furthermore, there is another possible scenario. The so-called current sheet is just an emission-enhanced region.

Dynamical Evolution of Newly Formed Structures After Magnetic Reconnection

“…The classical magnetic reconnection theories indicate that the topological exchange process occurs within a sheet-like current region. From the observations, the corresponding position is detected to be an emission-enhanced region (e.g., Figures 1(d), 3(c), 4(d3), 5(a3), and 5(d3)), which has been revealed by Ding et al (2024b). It is possible that the enhancement results from the pileup of heated plasmas.…”

“…In other words, the observed bright features can just be considered as the plasma sheets (Lee et al 2019;Reeves et al 2019) in the absence of the reconnection electric field information. Moreover, there is another possibility that the detected "current sheets" are a brightened segment of the reconnected structures or the postreconnection ones (Reeves et al 2019;Ding et al 2024b).…”

“…To investigate the dynamical characteristics of newly formed structures, we focus on magnetic reconnection events that have an explicit X-type configuration (e.g., Li et al 2016;Yan et al 2022;Ding et al 2024aDing et al , 2024b. The X-configuration consists of two sets of independent atmospheric structures, and the reconnection process, including the approaching of the atmospheric structures, the formation of the plasma sheet, and the evolution of the newly formed structures, is clearly observed.…”