Conservation of Total Escape from Hydrodynamic Planetary Atmospheres

Abstract

Atmosphere escape is one key process controlling the evolution of planets. However, estimating the escape rate in any detail is difficult because there are many physical processes contributing to the total escape rate. Here we show that as a result of energy conservation the total escape rate from hydrodynamic planetary atmospheres where the outflow remains subsonic is nearly constant under the same stellar XUV photon flux when increasing the escape efficiency from the exobase level, consistent with the energy limited escape approximation. Thus the estimate of atmospheric escape in a planet's evolution history can be greatly simplified.

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• A Super-Earth Transiting a Naked-Eye Star
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Cited by in corpus (4)

• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs
• Survival of Terrestrial N2-O2 Atmospheres in Violent XUV Environments through Efficient Atomic Line Radiative Cooling
• Possible Atmospheric Diversity of Low Mass Exoplanets, some Central Aspects
• Stellar Wind Effect on the Atmospheric Escape of Hot Jupiters and their Ly-$\alpha$ and H$\alpha$ transits