标题： 天王星和海王星挥发物源储层的关键大气特征 显示英文标题

标题： Key Atmospheric Signatures for Identifying the Source Reservoirs of Volatiles in Uranus and Neptune

摘要： 我们研究了挥发物输送到冰巨星大气中的几种输送情景的富集模式，考虑到唯一通过远程测定的确定结果，即碳丰度测量表明它们的包层具有高度超太阳金属丰度，即接近原始太阳星云的两个数量级以上。在核心吸积模型的框架下，只有以固态形式（非晶态冰、笼状化合物、纯冷凝物）将挥发物输送到这些行星，才能解释其包层明显的超太阳金属丰度。相反，由于冰粒通过各种雪线向内漂移，所有涉及以气态形式输送挥发物的机制都预测天王星和海王星的包层中丰度低于太阳。此外，即使盘不稳定性机制在我们的太阳系中仍存在疑问，但假设这两颗行星随后经历了氢-氦包层的侵蚀，它可能与观测到的天王星和海王星的超太阳金属丰度一致。对于每种考虑的输送情景得出的富集模式应该有助于解释未来通过大气进入探测器进行的原位测量。 显示英文摘要

摘要： We investigate the enrichment patterns of several delivery scenarios of the volatiles to the atmospheres of ice giants, having in mind that the only well constrained determination made remotely, i.e. the carbon abundance measurement, suggests that their envelopes possess highly supersolar metallicities, i.e. close to two orders of magnitude above that of the protosolar nebula. In the framework of the core accretion model, only the delivery of volatiles in solid forms (amorphous ice, clathrates, pure condensates) to these planets can account for the apparent supersolar metallicity of their envelopes. In contrast, because of the inward drift of icy particles through various snowlines, all mechanisms invoking the delivery of volatiles in vapor forms predict subsolar abundances in the envelopes of Uranus and Neptune. Alternatively, even if the disk instability mechanism remains questionable in our solar system, it might be consistent with the supersolar metallicities observed in Uranus and Neptune, assuming the two planets suffered subsequent erosion of their H-He envelopes. The enrichment patterns derived for each delivery scenario considered should be useful to interpret future in situ measurements by atmospheric entry probes.