Comparative Studies of the Interaction and Ionospheric Processes at a Variety of Different "Non-Magnetic" Solar System Bodies

该项目继续提供支助，以便能够扩大以前资助的关于快速流动的等离子体与非磁化太阳系天体相互作用的研究。在上一个项目中，对为陆地空间天气应用开发的综合数值方案进行了修改，以用于各种太阳系应用。很大一部分工作集中在以系统的方式开发“可能的最佳”磁流体力学(MHD)模型，以描述土卫六和火星上的这些相互作用和电离层现象。其结果是一个高空间分辨率，多物种，球形，霍尔，磁流体模型，可以计算太阳风相互作用过程，逃逸通量，以及相关的电离层现象。球面模型在火星和土卫六的电离层区域分别具有约10公里和35公里的网格分辨率，提供了对测量密度的非常好的模拟。该项目将扩大努力，将其他太阳系天体包括在内，以便进行比较研究；特别令人感兴趣的是木卫一、木卫二、土卫二和土卫二。通过分别求解不同物种的动量方程和能量方程，MHD程序将被修改为多流体。这些代码将用于调查与不同太阳系天体相关的化学和物理过程中的许多相似之处和重要差异。将使用的数值格式起源于计算流体力学领域，并可能在行星和比较大气学领域之外找到应用，例如全球气候变化建模。正在不断改进的基本MHD代码将在当前的空间气象工作中发挥作用。该项目将为一名女研究生提供部分支持。

This project provides continuing support to enable extension of previously funded investigation of the interaction of fast flowing plasma with non-magnetized solar system bodies. In the previous project, comprehensive numerical schemes that had been developed for terrestrial space weather applications were modified to be used for a variety of solar system applications. A significant fraction of the effort centered on the development, in a systematic fashion, of the "best possible" magnetohydrodynamic (MHD) models to describe these interactions and ionospheric phenomena at Titan and Mars. The result is a high spatial resolution, multi-species, spherical, Hall, magnetohydrodynamic model that can calculate the solar wind interaction processes, escape fluxes, and associated ionospheric phenomena. The spherical model has a grid resolution of about 10 km and 35 km in the ionospheric regions of Mars and Titan, respectively, providing very good simulations of the measured densities. This project will expand the effort to include other solar system bodies in order to undertake comparative studies; of particular interest are Io, Europa, Callisto, and Enceladus. The MHD code will be modified to be multi-fluid by solving separate momentum and energy equations for the different species. The codes will be applied to investigations of the many similarities and the important differences in the chemical and physical processes associated with the different solar system bodies. The numerical schemes to be used originated in the field of computational fluid dynamics and will likely find applications outside the field of planetary and comparative aeronomy, such as global climate change modeling. The basic MHD code that is being continually improved will be useful in current space weather efforts. The project will provide partial support for a female graduate student.