Brightness Distribution Across the Solar Disk in the Millimeter Range: Observations and Chromospheric Models

The study of center-to-limb brightness variation (CLV) curves is a convenient diagnostic tool for chromospheric plasma. Its primary expected characteristics include a gradual brightening from the disk center towards the limb and the existence of a bright narrow ring at the solar limb, caused by the contribution of emission from the hotter upper chromosphere and corona. An important CLV parameter is the solar radio radius, which depends on wavelength and can be considered an estimate of the chromospheric extent (height). This article presents a comparison of available observational CLV data with the calculated distributions obtained using modern realistic dynamic inhomogeneous chromospheric models.