Small-scale magnetic reconnection in the quiet Sun contributes to the heating of the solar atmosphere, but the extent of this contribution remains unclear. In this study, I examined the impact of quiet-Sun Ellerman bombs (QSEBs) on upper-atmosphere heating using high-resolution observations from the Swedish 1-m Solar Telescope (SST), along with coordinated data from the Interface Region Imaging Spectrograph (IRIS).
Using potential field extrapolations of the photospheric magnetic field, we explored the three-dimensional magnetic field topologies that link QSEBs to transition region Ultraviolet (UV) brightenings. When these events occur close to each other, QSEBs are found either along the polarity inversion line of a dipole or at different footpoints of a 3D null with a fan-spine topology. In such cases, QSEBs typically appear at the footpoints of the inner spine, outer spine, or the fan surface, depending on the local magnetic field strength. The UV brightenings occur near the 3D null point, with the height of the null point varying based on the inner spine’s field strength.
We also examined more intricate magnetic configurations involving interactions between multiple fan-spine structures. In one case, a smaller fan-spine topology was nested inside a larger one, with QSEBs occurring at the footpoints of the fan surfaces and a UV brightening located near the outer 3D null. In another instance, QSEBs appeared at a shared footpoint where two adjacent 3D nulls had interacting fan surfaces. We also observed chromospheric inverted-Y-shaped jets emerging near the QSEBs. In the first scenario, the jet closely followed regions of high squashing factor. To validate this flux emergence-driven reconnection scenario, we also compared our findings with numerical simulations using the Bifrost code, supporting the idea that small-scale reconnection can drive jet-like eruptions in the quiet Sun.
