# Numerical Simulations of the Evolution of Solar Active Regions: the Complex AR12565 and AR12567

## TL;DR

This paper uses 3D MHD simulations to study the evolution of two solar active regions, revealing their interconnected development and the formation of current sheets linked to solar eruptions.

## Contribution

It introduces a novel simulation approach combining observational extrapolations with MHD modeling to analyze the joint evolution of active regions AR12565 and AR12567.

## Key findings

- Active regions AR12565 and AR12567 evolved as a quadrupolar system.
- The second active region emerged under the loops of AR12565.
- A current sheet formed between the regions, facilitating explosive solar events.

## Abstract

We have performed numerical magnetohydrodynamic (MHD) simulations of two closed active regions (AR). The input magnetic field values were the coronal magnetic field computed as extrapolation coronal from observations of the photospheric magnetic field. The studied active regions, NOAA AR12565 and AR12567, were registered as different bipolar region. Our investigation, the 3D coronal extrapolations, as well as the numerical MHD experiments, revealed that actually they evolved together as a quadrupolar active region. The second region emerged later under the loops system of AR12565 and separated from this one. A natural current sheet formed between then and it plays an important role in the explosive events (flares and coronal mass ejections) occurrence.