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

这项提议将进一步发展一种混合流体/动力学模式，并使用该模式来研究极地风。在该模式中，极地风的热电子特征用流体计算来描述，而超热电子特征以及H和O离子在全球环境中用动力学模型来描述。考虑了物种间的哥伦布碰撞，并自洽地计算了双极电场。这种方法是第一个能够将光电子的全球碰撞物理纳入自洽描述的方法。在探索性计算中，产生了从亚音速碰撞区域到超音速无碰撞区域连续变化的全球定常极地风解。这里的研究将首先致力于参数研究，以便更好地了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的影响。模型调查的结果将与从DE和Akebono卫星上的实验获得的极风数据获得的结果进行比较。

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.