论文标题
海王星的电离层和平流层的1D光化学模型
1D photochemical model of the ionosphere and the stratosphere of Neptune
论文作者
论文摘要
海王星仍然是一个神秘的世界，值得进一步的探索，并且是一个未来行星任务的高优先权目标，以便更好地了解冰巨星的形成和发展。我们已经开发了一个海王星大气的耦合离子中性1D光化学模型，以研究碳氢化合物和氧气的起源和进化。最新的化学方案源自一种用于泰坦大气的一种，这与卡西尼 - 奇数的观察结果达成了良好的协议。我们获得的主要结果如下：离子中性化学偶联在海王星大气中产生芳香剂（尤其是苯），其丰度相对较高。我们的模型结果与观察结果非常吻合（考虑模型不确定性）。位于10 $^{-5} $ mbar的压力水平上方的大气层中存在两个电离层峰，约为10 $^{ - 3} $ MBAR。海王星上层大气中氧气的涌入对许多离子的浓度有影响。我们表明，对海王星大气的原位探索将为有关氧气的起源和离子化学的贡献提供的光化学模型提供非常有趣的约束。对上大气化学的精确描述对于更好地理解该星球的内部组成和形成过程至关重要。
Neptune remains a mysterious world that deserves further exploration and is a high-priority objective for a future planetary mission in order to better understand the formation and evolution of ice giant planets. We have developed a coupled ion-neutral 1D photochemical model of Neptune's atmosphere to study the origin and evolution of the hydrocarbons and the oxygen species. The up-to-date chemical scheme is derived from one used for Titan's atmosphere, which led to good agreements with the Cassini-CIRS observations for oxygen species and the main hydrocarbons. The main results we obtain are the following: The ion-neutral chemistry coupling produces aromatics (and benzene in particular) in the atmosphere of Neptune with relatively high abundances. Our model results are in good agreement with observations (taking model uncertainties into account). Two ionospheric peaks are present in the atmosphere located above the pressure level of 10$^{-5}$ mbar and around 10$^{-3}$ mbar. The influx of oxygen species in the upper atmosphere of Neptune has an effect on the concentration of many ions. We show that in situ exploration of Neptune's atmosphere would provide very interesting constraints for photochemical models concerning in particular the origin of oxygen species and the contribution of ion chemistry. A precise description of upper atmospheric chemistry is crucial for a better understanding of the internal composition and the formation processes of this planet.
