The Chromospheric Solar Millimeter-wave Cavity; a Common Property in the Semi-empirical Models

TL;DR

This study reveals that the Chromospheric Solar Millimeter-wave Cavity (CSMC), a region of local optical thinness at millimeter wavelengths, is a common feature in semi-empirical models of the solar chromosphere, linked to the temperature minimum.

Contribution

It demonstrates that the CSMC is a universal property in semi-empirical models, enhancing understanding of solar chromospheric structure at millimeter wavelengths.

Findings

CSMC is present in all studied semi-empirical models.

The CSMC correlates with the temperature minimum in the chromosphere.

The study improves modeling of solar radio emission at millimeter wavelengths.

Abstract

The semi-empirical models of the solar chromosphere are useful in the study of the solar radio emission at millimeter - infrared wavelengths. However, current models do not reproduce the observations of the quiet sun. In this work we present a theoretical study of the radiative transfer equation for four semi- empirical models at these wavelengths. We found that the Chromospheric Solar Milimeter-wave Cavity (CSMC), a region where the atmosphere becomes locally optically thin at millimeter wavelengths, is present in the semi-empirical models under study. We conclude that the CSMC is a general property of the solar chromosphere where the semi-empirical models shows temperature minimum.