Abstract
The Ellerman bombs are small-scale explosive events that occur at the base of the chromosphere and exhibit a characteristic spectral profile, showing absorption in the Hα line center and significant brightening in the wing. While magnetic reconnection is considered to be the mechanism of their occurrence, the details remain unresolved. Therefore, the aim of this study is to elucidate the temporal evolution of the three-dimensional structure of Ellerman bombs through their spectral characteristics. Using the horizontal spectrograph at the Hida Observatory, Kyoto University, in October 2022, we conducted spectroscopic observations of Ellerman bombs that occurred in the vicinity of sunspots in active regions NOAA13124 and NOAA13135, using the Hα and Ca II K lines, and obtained the temporal variations of physical quantities such as velocity, temperature, and brightness at each wavelength. As a result, we observed magnetic reconnection at the base of the chromosphere in the Hα line, and bi-directional flow resulting from it. Furthermore, we confirmed a correlation between the increase in brightness and the subsequent rise in velocity in the wing. In the Ca II K line, we considered magnetic reconnection to occur below the middle of the chromosphere, and we found a similar correlation between the velocity and brightness of the K2 component as in the Hα line wing.
https://ror.org/00sjd5653 
