Model Development and Theory/Data Closure for the Photoelectron-Driven Polar Wind

光电子驱动极地风的模型开发和理论/数据收敛

• 批准号: 9634599
• 负责人: Tom Chang
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-01-01 至 2000-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9634599&HistoricalAwards=false
• 关键词: Model; Development; Theory; Data; Closure

This proposal will further develop a hybrid fluid/kinetic model and use the model to investigate the polar wind. In this model, thermal electron features of the polar wind are described by fluid calculations while the suprathermal electron features, as well as H+ and O+ ions are described using a kinetic model in a global environment. Columbo collisions among species are taken into account and the ambipolar electric field is computed self consistently. This approach is the first to be able to incorporate the global collisional physics of photoelectrons into a self- consistent description. Global steady-state polar wind solutions that vary continuously from a subsonic collisional regime to a supersonic collisionless regime have been generated in exploratory calculations. The investigation here will be first devoted to parametric studies in order to better understand the complex inter- relations between various ionospheric boundary conditions and their effects on polar wind outflow. Results of the model investigations will be compared with results being obtained from polar wind data obtained from experiments on the DE and Akebono satellites.

该提案将进一步开发混合流体/动力学模型，并使用该模型来研究极地风。 在该模型中，极地风的热电子特征通过流体计算来描述，而超热电子特征以及H+和O+离子则使用全球环境中的动力学模型来描述。 考虑了物种之间的哥伦布碰撞，并且自洽地计算双极电场。 这种方法是第一个能够将光电子的全局碰撞物理纳入自洽描述的方法。 在探索性计算中已经生成了从亚音速碰撞状态到超音速无碰撞状态连续变化的全球稳态极地风解。 这里的调查将首先致力于参数研究，以便更好地理解各种电离层边界条件之间的复杂相互关系及其对极地风流出的影响。 模型研究的结果将与从 DE 和 Akebono 卫星实验中获得的极地风数据的结果进行比较。