Constraining Titan's Seasonal Tropospheric Haze Distribution

土卫六是土星最大的卫星，不同于太阳系中的其他卫星。厚厚的浓雾笼罩着土卫六，影响了土卫六湖泊的组成和表面的侵蚀。该项目将模拟这种独特的雾霾的季节性丰度和分布，以了解驱动大气循环的物理过程。这个项目将通过开发用户友好的图形用户界面来吸引更广泛的社区，这将向当前的研究生和本科生介绍辐射传输代码背后的复杂物理过程。这项工作将促进学术界和工业界之间建立独特的伙伴关系，从而提高对地球共同体至关重要的大气模型的科学回报。了解土卫六雾霾的全球分布和性质对于揭示雾霾在全球环流、辐射平衡和大气化学中所起的关键作用至关重要。迄今为止，由于目前的辐射传输代码无法准确模拟大气中复杂的吸收和散射效应，因此很难约束气溶胶的循环和分布。这个项目将探索土卫六上层和下层大气之间的季节性和动态联系。该项目将扩大两个主要的辐射转移代码，以纳入新的甲烷线清单。该团队还将改进大气辐射传输方程的数值处理，以准确模拟垂直不均匀、非等温、平面平行层中的散射、吸收和发射。研究小组将通过对惠更斯号着陆点的地面和太空观测来验证这些模型，并将绘制出土卫六对流层中雾霾分布的第一张地图。精确的辐射传输代码的开发不仅对土卫六社区，而且对（外）行星社区都至关重要。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Titan, the largest moon of Saturn, is unlike any other moon in the solar system. A thick hazy atmosphere enshrouds the moon and affects the composition of Titan's lakes and erosion of the surface. The project will model the seasonal abundance and distribution of this unique haze in order to understand the physical processes that drive the circulation of the atmosphere. This project will engage the broader community through the development of user-friendly GUIs that will introduce current graduate and undergraduate students to the complex physical processes behind radiative transfer codes. This work will stimulate a unique partnership between academia and industry that will enhance the scientific return of atmospheric models essential to the planetary community. Understanding the global distribution and properties of Titan’s hazes is paramount for revealing the critical roles hazes play in global circulation, radiative balance and atmospheric chemistry. To date, it has been difficult to constrain the circulation and distribution of aerosols due to the inability of current radiation transfer codes to accurately model the complex absorption and scattering effects in the atmosphere. This program will explore the seasonal and dynamical connections between Titan’s upper and lower atmospheres. The project will expand two principal radiative transfer codes to incorporate newly available methane line lists. The team will also improve the numerical treatment of atmospheric radiative-transfer equations to accurately model scattering, absorption, and emission in vertically inhomogeneous, non-isothermal, plane-parallel layers. The team will validate the models using a combination of ground and space-based observations of the Huygens landing site and will produce the first maps of the distribution of haze in Titan’s troposphere. The development of accurate radiative transfer codes is of vital importance to not only the Titan community but also for the (exo)planetary communities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.