论文标题
大气稳定性和潮汐锁定的岩石行星的崩溃
Atmospheric stability and collapse on tidally locked rocky planets
论文作者
论文摘要
在大型时间尺度上，陆地行星可能会被潮汐力驱动到自旋轨道同步旋转。在这种特殊的配置中，行星表现出永久的白天和夜间，这可能会引起强烈的昼夜温度梯度。夜间温度取决于昼夜热重新分布的效率，并确定了大气在塌陷中的稳定性。为了更好地限制位于其宿主恒星宜居区的岩石行星的大气稳定性，气候和表面条件，因此，了解热重新分布的复杂机制至关重要。在早期作品并假设热力学的基础上，我们在辐射转移，日间对流和大规模大气循环的情况下，开发了分析模型的层次结构。这些模型有两种类型：零维的两层方法和两列辐射式接收 - 助式上间的网站（RCSU）模型。它们产生了分析解决方案和缩放定律，这些定律表征了塌陷压力对物理特征的依赖性，这与使用3D全球气候模型（GCM）获得的结果相比。 The analytical theory captures (i) the dependence of temperatures on atmospheric opacities and scattering in the shortwave and in the longwave, (ii) the behaviour of the collapse pressure observed in GCM simulations at low stellar fluxes that are due to the non-linear dependence of the atmospheric opacity on the longwave optical depth at the planet's surface, (iii) the increase of stability generated by dayside sensible heating, and （iv）行星大小的增加引起的稳定性下降。
Over large timescales, a terrestrial planet may be driven towards spin-orbit synchronous rotation by tidal forces. In this particular configuration, the planet exhibits permanent dayside and nightside, which may induce strong day-night temperature gradients. The nightside temperature depends on the efficiency of the day-night heat redistribution and determines the stability of the atmosphere against collapse. To better constrain the atmospheric stability, climate, and surface conditions of rocky planets located in the habitable zone of their host star, it is thus crucial to understand the complex mechanism of heat redistribution. Building on early works and assuming dry thermodynamics, we developed a hierarchy of analytic models taking into account the coupling between radiative transfer, dayside convection, and large-scale atmospheric circulation in the case of slowly rotating planets. There are two types of these models: a zero-dimensional two-layer approach and a two-column radiative-convective-subsiding-upwelling (RCSU) model. They yield analytical solutions and scaling laws characterising the dependence of the collapse pressure on physical features, which are compared to the results obtained by early works using 3D global climate models (GCMs). The analytical theory captures (i) the dependence of temperatures on atmospheric opacities and scattering in the shortwave and in the longwave, (ii) the behaviour of the collapse pressure observed in GCM simulations at low stellar fluxes that are due to the non-linear dependence of the atmospheric opacity on the longwave optical depth at the planet's surface, (iii) the increase of stability generated by dayside sensible heating, and (iv) the decrease of stability induced by the increase of the planet size.
