Reassessing Ocean Retention Rates: The Role of Ocean Formation Time Assumptions in Rocky Exoplanet Studies

Abstract In this work, we aim to model ocean and atmospheric mass loss in exoplanets with varying orbital parameters to assess the impact of simulation assumptions on conclusions on planetary habitability. In particular, we examine how altering the time at which a planet’s ocean is assumed to form may affect long-term inferred ocean retention rates. To study this relationship, we used VPlanet, a modular code that has the ability to model water loss on exoplanets. Using a suite of VPlanet simulations, we found that the stellar age at which a planet is assumed to form its oceans has a noticeable effect on the computed planetary water loss over Gyr timescales. This suggests that future research on ocean loss in exoplanets should account for the variability in the timing of when planets are able to form oceans.