Solar-cycle and Latitude Variations in the Internetwork Magnetism

Abstract

The importance of the quiet-Sun magnetism is that it is always there to a greater or lesser extent, being a constant provider of energy, independently of the solar cycle phase. The open questions about the quiet-Sun magnetism include those related to its origin. Most people claim that the local dynamo action is the mechanism that causes it. This fact would imply that the quiet-Sun magnetism is nearly the same at any location over the solar surface and at any time. Many works claim that the quiet Sun does not have any variation at all, although a few of them raise doubt on this claim and find mild evidence of a cyclic variation in the the quiet-Sun magnetism. In this work, we detect clear variations in the internetwork magnetism both with latitude and solar cycle. In terms of latitude, we find an increase in the averaged magnetic fields toward the solar poles. We also find long-term variations in the averaged magnetic field at the disk center and solar poles, and both variations are almost anticorrelated. These findings do not support the idea that the local dynamo action is the unique factory of the quiet-Sun magnetism.

Global Impact of Emerging Internetwork Fields on the Low Solar Atmosphere

“…Recent Hinode observations showed that IN fields mainly appear in the form of magnetic bipoles in the photosphere (Gošić et al 2022), likely generated by small-scale surface dynamo (Rempel 2014), but other scenarios are also possible (Pietarila et al 2011;Martínez González et al 2012;Trelles Arjona et al 2023). According to some numerical models (Isobe et al 2008;Amari et al 2015;Moreno-Insertis et al 2018), andobservations (e.g., Martínez González &Bellot Rubio 2009;Martínez González et al 2010;Gošić et al 2021), these fields may upon appearance in the photosphere rise through the lower atmosphere, and locally heat the chromosphere and transition region.…”