Energy transport and vorticity in photospheric vortex tubes

The Daniel K. Inouye Telescope is expected to improve the quality of the solar observations by providing us more accurate and reliable inversions of the magnetic, and velocity fields. This will allow us to perform various calculations related to the Poynting flux and validate the findings from the simulations concerning the role of vortices in electromagnetic energy transport. In this work, we applied the Instantaneous Vorticity Deviation method to detect the three-dimensional photospheric vortex tubes (Silva et al., ApJ, 2021) in the MURaM simulation of a solar plage region. The detected vortices appear among regions with high-temperature gradients. From the analysis of the radial profile for vorticity, it follows that the main vorticity generation mechanism is the magnetic baroclinic term. Hence, the magnetic field plays a crucial role in the vortex evolution. The temperature inside the vortex tends to vary over time, with most vortices experiencing cooling at their centres and heating in the regions closer to their boundaries. Our findings indicate that the vortex dynamics mostly create regions with strong temperature gradients as the vortex pushes the plasma out, increasing pressure and density, which leads to a hot plasma region. We also found that the transport of energy by Poynting flux is not uniform within the vortex. In fact, the distribution of vertical Poynting flux inside the vortex tubes indicates a convective motion of electromagnetic energy across the lower solar atmosphere. Although there is both upward and downward Poynting flux in vortices, importantly, there is a dominant upward propagating energy flux of 1.38x108 ergs/(s cm2), which is sufficient to explain chromospheric temperatures. Horizontal plasma motions generate the vertical Poynting flux inside the analysed vortices, and it tends to be greater at the vortex boundary, indicating that plasma heating may occur between vortices.