REVIEW article

Front. Astron. Space Sci.
Sec. Stellar and Solar Physics
doi: 10.3389/fspas.2022.981205

The dynamic chromosphere at millimeter wavelengths

 Alexander Nindos1*, Spiros Patsourakos1,  Shahin Jafarzadeh2, 3 and  Masumi Shimojo4, 5
  • 1University of Ioannina, Greece
  • 2Max Planck Institute for Solar System Research, Germany
  • 3Rosseland Centre for Solar Physics, Faculty of Mathematics and Natural Sciences, University of Oslo, Norway
  • 4National Astronomical Observatory of Japan (NINS), Japan
  • 5Department of Astronomical Science, The Graduate University of Advanced Studies (SOKENDAI), Japan
Provisionally accepted:
The final, formatted version of the article will be published soon.

The chromosphere is one of the most complex and dynamic layers of the solar atmosphere. The dynamic phenomena occur on different spatial and temporal scales, not only in active regions but also in the so-called quiet Sun. In this paper we review recent advances in our understanding of these phenomena that stem from the analysis of observations with the Atacama Large Millimeter/submillimeter Array (ALMA). The unprecedented sensitivity as well as spatial and temporal resolution of ALMA at millimeter wavelengths have advanced the study of diverse phenomena such as chromospheric $p$-mode-like and high-frequency oscillations, as well as small-scale, weak episodes of energy release, including shock waves. We review the most important results of these studies by highlighting the new aspects of the phenomena that have revealed as well as the new questions and challenges that have generated.

Keywords: Sun solar radio emission, Sun chromosphere, Sun quiet Sun, Sun active regions, Sun oscillations, Sun MHD waves

Received: 29 Jun 2022; Accepted: 27 Jul 2022.

Copyright: © 2022 Nindos, Patsourakos, Jafarzadeh and Shimojo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Mx. Alexander Nindos, University of Ioannina, Ioannina, Greece