论文标题
失去海洋：组成对冲击驱动大气损失的热成分的影响
Losing Oceans: The Effects of Composition on the Thermal Component of Impact-driven Atmospheric Loss
论文作者
论文摘要
太阳系的地面行星的形成结束了一段巨大的影响。以前的著作研究了由月球形成冲击的冲击冲击引起的挥发性损失，发现最多20％至30％的大气损失，基本上没有海洋损失。但是，巨大的影响也导致热加热，这可能会导致大气中通过帕克型风能逃脱。在这里，我们表明，如果存在于氢气的大气中，则H2O和其他高均值分子量超过了这种热风，可以在热风中有效损失，从而实质上改变了陆地行星的最终挥发性清单。具体而言，我们证明了具有原始地球的火星大小的胚胎的巨大影响可以消除几个地球海洋价值的H2O和其他较重的挥发性物种，以及原始的氢为主的大气。这些结果可能可以解释地球光质量预算及其耗尽的Xenon库存中观察到的耗竭，这表明在积聚结束时，地球在大气中产生了重大的大气损失。由于行星胚胎足够大，足以吸收原始氢信封，并且巨大的影响是随机的，并且与其他早期大气进化过程同时发生，因此我们的结果表明，陆地行星挥发预算的多样性广泛。
The formation of the solar system's terrestrial planets concluded with a period of giant impacts. Previous works examining the volatile loss caused by the impact shock in the moon-forming impact find atmospheric losses of at most 20-30 per cent and essentially no loss of oceans. However, giant impacts also result in thermal heating, which can lead to significant atmospheric escape via a Parker-type wind. Here we show that H2O and other high-mean molecular weight outgassed species can be efficiently lost through this thermal wind if present in a hydrogen-dominated atmosphere, substantially altering the final volatile inventory of terrestrial planets. Specifically, we demonstrate that a giant impact of a Mars-sized embryo with a proto-Earth can remove several Earth oceans' worth of H2O, and other heavier volatile species, together with a primordial hydrogen-dominated atmosphere. These results may offer an explanation for the observed depletion in Earth's light noble gas budget and for its depleted xenon inventory, which suggest that Earth underwent significant atmospheric loss by the end of its accretion. Because planetary embryos are massive enough to accrete primordial hydrogen envelopes and because giant impacts are stochastic and occur concurrently with other early atmospheric evolutionary processes, our results suggest a wide diversity in terrestrial planet volatile budgets.
