Updated Mean Opacity Tables for Giant Planet Atmospheres

Mean opacities are essential tools for modeling the atmospheres, interiors, and thermal evolution of exoplanets. Although significant progress has been made in recent years in developing molecular line lists, many widely used mean opacity tables still rely on outdated data and are therefore subject to considerable uncertainties.

In this work, we present new Rosseland and Planck mean opacity tables relevant to the atmospheres of giant planets. These tables are based on state-of-the-art molecular line lists and include updated pressure broadening treatments. They extend to higher pressures than commonly used tables, making them particularly relevant for modeling planetary interiors and deep atmospheres. We compare our results to existing opacity tables and investigate their impact on key properties of planets. In addition, we assess the influence of solid grains on the opacities by performing calculations for various grain sizes.