# A Cancellation Nanoflare Model for Solar Chromospheric and Coronal Heating II. 2D Theory and Simulations

## TL;DR

This paper develops a 2D resistive MHD simulation to study magnetic flux cancellation as a mechanism for solar atmospheric heating, confirming analytical estimates and exploring atmospheric responses like hot and cool ejections.

## Contribution

It advances the theory by providing 2D simulations that validate analytical energy estimates and examine the atmospheric effects of magnetic reconnection during flux cancellation.

## Key findings

- Simulation results agree qualitatively with analytical energy estimates.
- Reconnection can produce hot coronal-like ejections or cool surges depending on height.
- Atmospheric responses include hot coronal loops and cool spicule-like structures.

## Abstract

Recent observations at high spatial resolution have shown that magnetic flux cancellation occurs on the solar surface much more frequently than previously thought, and so this led Priest et al 2018 to propose magnetic reconnection driven by photospheric flux cancellation as a mechanism for chromospheric and coronal heating. In particular, they estimated analytically the amount of energy released as heat and the height of the energy release during flux cancellation. In the present work, we take the next step in the theory by setting up a two-dimensional resistive MHD simulation of two canceling polarities in the presence of a horizontal external field and a stratified atmosphere in order to check and improve upon the analytical estimates. Computational evaluation of the energy release during reconnection is found to be in good qualitative agreement with the analytical estimates. In addition, we go further and undertake an initial study of the atmospheric response to reconnection. We find that, during the cancellation, either hot ejections or cool ones or a combination of both hot and cool ejections can be formed, depending on the height of the reconnection location. The hot structures can have the density and temperature of coronal loops, while the cooler structures are suggestive of surges and large spicules.