# Bombs and flares at the surface and lower atmosphere of the Sun

## TL;DR

This paper uses 3D radiative MHD simulations to explore how magnetic flux emergence causes various transient energetic events like Ellerman bombs, UV bursts, and small flares in the Sun's lower atmosphere, enhancing understanding of solar magnetic activity.

## Contribution

It presents the first realistic 3D simulations linking magnetic flux emergence to multiple types of transient solar phenomena across different atmospheric layers.

## Key findings

- Reconnection triggers Ellerman bombs in the photosphere.
- UV bursts occur in the mid/low chromosphere due to magnetic activity.
- Small flares up to 10^6 K are generated in the upper chromosphere.

## Abstract

A spectacular manifestation of solar activity is the appearance of transient brightenings in the far wings of the H$\alpha$ line, known as Ellerman bombs (EBs). Recent observations obtained by the Interface Region Imaging Spectrograph (IRIS) have revealed another type of plasma "bombs" (UV bursts) with high temperatures of perhaps up to $8\times 10^4$ K within the cooler lower solar atmosphere. Realistic numerical modeling showing such events is needed to explain their nature. Here, we report on 3D radiative magneto-hydrodynamic simulations of magnetic flux emergence in the solar atmosphere. We find that ubiquitous reconnection between emerging bipolar magnetic fields can trigger EBs in the photosphere, UV bursts in the mid/low chromosphere and small (nano-/micro-) flares ($10^6$ K) in the upper chromosphere. These results provide new insights on the emergence and build up of the coronal magnetic field and the dynamics and heating of the solar surface and lower atmosphere.