BAYESIAN EVOLUTION MODELS FOR JUPITER WITH HELIUM RAIN AND DOUBLE-DIFFUSIVE CONVECTION
BAYESIAN EVOLUTION MODELS FOR JUPITER WITH HELIUM RAIN AND DOUBLE-DIFFUSIVE CONVECTION
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具有氦雨和双扩散对流的木星贝叶斯演化模型
DOI：
10.3847/0004-637x/832/2/113
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
K. Moore
中科院分区：
文献类型：
--
作者：
C. Mankovich;J. Fortney;K. Moore
氢和氦在足够冷的时候会发生分离，这关系到所有巨大行星在大分离时的演化，这些大分离大约等于或低于木星质量。我们模拟木星的热演化，包括其不断变化的氦分布的从头计算模拟结果的氦不溶性金属氢。经过4 Gyr的均匀演化，分化建立了一个薄的氦梯度低于1毫巴，动态稳定的流体对流。该地区经历过稳定的双扩散对流（ODDC），其弱的热传输维持超绝热温度梯度。与通用参数化的ODDC效率，模型可以调和木星的intrinsix通量，大气中的氦含量，半径在太阳系的年龄，如果Lorenzen等人的H-He相图被翻译到较低的温度。我们投在MCMC框架的进化模型，探索数以万计的进化序列，检索概率分布的总重元素质量，超绝热的温度梯度由于ODDC，和相图扰动。所采用的SCvH-I状态方程（EOS）有利于低效的ODDC，从而形成热边界层，允许分子包层快速冷却，而更深的内部实际上随着时间的推移而升温。如果用一个附加的自由参数来模拟较冷或较暖EOS的影响，则模型更倾向于那些比SCvH-I更冷的EOS。在这种情况下，超绝热性是适度的，并且变暖和冷却的深部内部同样可能。
Hydrogen and helium demix when sufficiently cool, and this bears on the evolution of all giant planets at large separations at or below roughly a Jupiter mass. We model the thermal evolution of Jupiter, including its evolving helium distribution following results of ab initio simulations for helium immiscibility in metallic hydrogen. After 4 Gyr of homogeneous evolution, differentiation establishes a thin helium gradient below 1 Mbar that dynamically stabilizes the fluid to convection. The region undergoes overstable double-diffusive convection (ODDC), whose weak heat transport maintains a superadiabatic temperature gradient. With a generic parameterization for the ODDC efficiency, the models can reconcile Jupiter’s intrinsix flux, atmospheric helium content, and radius at the age of the solar system if the Lorenzen et al. H–He phase diagram is translated to lower temperatures. We cast the evolutionary models in an MCMC framework to explore tens of thousands of evolutionary sequences, retrieving probability distributions for the total heavy-element mass, the superadiabaticity of the temperature gradient due to ODDC, and the phase diagram perturbation. The adopted SCvH-I equation of state (EOS) favors inefficient ODDC such that a thermal boundary layer is formed, allowing the molecular envelope to cool rapidly while the deeper interior actually heats up over time. If the overall cooling time is modulated with an additional free parameter to imitate the effect of a colder or warmer EOS, the models favor those that are colder than SCvH-I. In this case the superadiabaticity is modest and warming and cooling deep interiors are equally likely.
影响因子：
8.7
作者：
French, Martin;Becker, Andreas;Redmer, Ronald
通讯作者：
Redmer, Ronald
H/He 分层和土星的冷却行为
影响因子：
3.2
作者：
Püstow R;Nettelmann N;Lorenzen W;Redmer R.
通讯作者：
Redmer R.