Hydrodynamic escape of multicomponent exoplanet atmospheres of terrestrial-type exoplanets

类地行星被定义为具有明显凝结表面的行星，这些表面可能是液体，冰或岩石。这类行星可能基本上没有大气层（如水星），也可能有稀薄的大气层（大气层只占行星可观测半径的一小部分），或者可能有非常厚的包层，如从原行星盘吸积而来的分子氢包层。行星大气是由各种大气逃逸过程塑造而成的，其中流体动力逃逸是行星演化早期最重要的过程。一个重要的问题是什么样的大气可以在绕M星运行的行星上生存（或再生），M星是宇宙中最常见的星星形式，但在年轻时提供了一个有利于流体动力学逃逸的环境。该项目的目标是进一步了解这种逃逸，特别是了解重物质，如氮（我们所知道的生命所必需的）是否可以逃逸。这将是通过应用先进的计算方法，以一维可压缩多物种流体力学，最终耦合逃逸模型的大气化学模型和通量的成分从岩浆海洋在较低的boundary.There没有公司或正式的合作者参与，虽然当然通常的网络牛津大学内外的非正式合作者将不时参与。

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.