The influence of surface $CO_{\mathrm{2}}$ condensation on the evolution of warm and cold rocky planets orbiting Sun-like stars

TL;DR

This study investigates how surface $CO_{2}$ condensation affects the long-term habitability of rocky planets around Sun-like stars, considering different initial thermal states and star types using an advanced energy balance model.

Contribution

It introduces an energy balance model to analyze $CO_{2}$ ice condensation on warm and cold planets across various star types, extending previous models to include diverse initial conditions.

Findings

Warm start planets have a reduced range of $CO_{2}$ ice condensation zones.

Star type does not significantly influence condensation zones, but hotter stars increase the habitable zone fraction affected.

Classical habitable zone limits remain valid for warm start scenarios.

Abstract

The habitable zone is the region around a star where standing bodies of liquid water can be stable on a planetary surface. Its width is often assumed to be dictated by the efficiency of the carbonate-silicate cycle, which has maintained habitable surface conditions on our planet for billions of years. This cycle may be inhibited by surface condensation of significant amounts of $CO_{\mathrm{2}}$ ice, which is likely to occur on distant planets containing high enough levels of atmospheric $CO_{\mathrm{2}}$. Such a process could permanently trap $CO_{\mathrm{2}}$ ice within the planet, threatening its long-term habitability. Recent work has modeled this scenario for initially cold and icy planetary bodies orbiting the Sun. Here, we use an advanced energy balance model to consider both initially warm and cold rapidly-rotating planets orbiting F - K stars. We show that the range of orbital distances where significant surface $CO_{\mathrm{2}}$ ice condensation occurs is significantly reduced for warm start planets. Star type does not affect this conclusion, although surface $CO_{\mathrm{2}}$ ice condenses over a larger fraction of the habitable zone around hotter stars. The warm start simulations are thus consistent with 1-D model predictions, suggesting that the classical habitable zone limits in those earlier models are still valid. We also find that the cold start simulations exhibit trends that are consistent with those of previous work for the Sun although we now extend the analysis to other star types.