The importance of horizontal Poynting flux in the solar photosphere

作     者：Silva, Suzana S.A. Murabito, Mariarita Jafarzadeh, Shahin Stangliani, Marco Verth, Gary Ballai, Istvan Fedun, Viktor 

作者机构：Plasma Dynamics Group Department of Automatic Control and Systems Engineering University of Sheffield Sheffield United Kingdom Department of Physics Aeronautics Institute of Technology São José dos Campos Brazil INAF - Osservatorio Astronomico di Roma Via Frascati33 Monte Porzio Catone RM 00078 Italy Max Planck Institute for Solar System Research Justus-von-Liebig-Weg 3 Göttingen37077 Germany Rosseland Centre for Solar Physics University of Oslo P.O. Box 1029 Blindern OsloNO-0315 Norway ASI Italian Space Agency Via del Politecnico snc Rome00133 Italy Plasma Dynamics Group School of Mathematics and Statistics University of Sheffield Sheffield United Kingdom 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2022年

核心收录：

主　　题：Magnetohydrodynamics 

摘      要：The electromagnetic energy flux in the lower atmosphere of the Sun is a key tool to describe the energy balance of the solar atmosphere. Current investigations on energy flux in the solar atmosphere focus primarily on the vertical electromagnetic flux through the photosphere, ignoring the Poynting flux in other directions and its possible contributions to local heating. Based on a realistic Bifrost simulation of a quiet-Sun (coronal hole) atmosphere, we find that the total electromagnetic energy flux in the photosphere occurs mainly parallel to the photosphere, concentrating in small regions along intergranular lanes. Thereby, it was possible to define a proxy for this energy flux based on only variables that can be promptly retrieved from observations, namely, horizontal velocities of the small-scale magnetic elements and their longitudinal magnetic flux. Our proxy accurately describes the actual Poynting flux distribution in the simulations, with the electromagnetic energy flux reaching 1010 erg cm−2 s−1. To validate our findings, we extended the analysis to SUNRISE/IMaX data. First, we show that Bifrost realistically describes photospheric quiet-Sun regions, as the simulation presents similar distributions for line-of-sight magnetic flux and horizontal velocity field. Second, we found very similar horizontal Poynting flux proxy distributions for the simulated photosphere and observational data. Our results also indicate that the horizontal Poynting flux in the observations is considerably larger than the vertical electromagnetic flux from previous observational estimates. Therefore, our analysis confirms that the electromagnetic energy flux in the photosphere is mainly horizontal and is most intense in localized regions along intergranular lanes. Copyright © 2022, The Authors. All rights reserved.