Hydrodynamic escape of multicomponent exoplanet atmospheres of terrestrial-type exoplanets

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Terrestrial planets are defined as planets with a distinct condensed surface, which may be liquid, ice or rock. Such planets may be essentially free of atmosphere (such as Mercury), may have thin atmospheres in the sense of the atmosphere making up a small portion of the observable radius of the planet, or may have very thick envelopes, such as molecular hydrogen envelopes that may be accreted from the protoplanetary disks. Planetary atmospheres are sculpted by various atmospheric escape processes among which hydrodynamic escape is the most important in early stages of a planet's evolution. One important question is what kinds of atmospheres can survive (or be regenerated) on planets orbiting M stars, which are the most common form of star in the Univers, but provide an environment conducive to hydrodynamic escape when young. The goal of this project is to further the understanding of such escape, and particular the understanding of whether heavy species such as nitrogen (essential to life as we know it) can escape. This will be done by applying advanced computational methods to 1D compressible multispecies hydrodynamics, ultimately coupling the escape model to models of atmospheric chemistry and fluxes of constituents from a magma ocean at the lower boundary.There are no companies or formal collaborators involved, though of course the usual web of informal collaborators within and outside Oxford will be involved from time to time.