Magnetotail Dynamics and Auroral Wave-Particle Interactions

磁尾动力学和极光波粒相互作用

• 批准号: 8703301
• 负责人: Theodore Speiser
• 金额: $ 21.5万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-06-15 至 1991-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8703301&HistoricalAwards=false
• 关键词: Magnetotail; Dynamics; Auroral; Wave; Particle

The interactions between the solar wind and the Earth's magnetosphere are responsible for the complex dissipative processes which control the dynamics of the near earth environment. The study of these processes is the basic theme of solar-terrestrial research. The plasma sheet, its boundary layer, and the high latitude auroral region are of central importance in the understanding of these processes. The existence of the plasma sheet in the geomagnetic tail and the dawn-to-dusk electric field across the tail implies there is a significant energization of the particles carrying the crosstail current. This energization of particles in the tail represents ~2% of the total energy carried by the solar wind over an area equal to the cross section of the dayside magnetosphere, and thus this energization is an important, and perhaps the dominant means by which solar wind energy is transferred to magnetospheric particles. Current sheet acceleration of ions is responsible for the unstable ion beams found in the plasma sheet boundary layer (PSBL). The resulting motion of both ion and electron particle populations are the likely cause not only of the formation of the isotropic plasma sheet, but of the high latitude potential structure responsible for discrete arcs in the auroral region. Discrete auroral arcs are associated with regions of upward current carried by downward precipitating electrons which have been accelerated through a field-aligned potential difference of 10,000votts. Cold ionospheric ions are accelerated upward by the same potential drop. This grant is composed of three projects: A) magnetotail particle dynamics, B) broadband turbulence and particle diffusion in the plasma sheet, and C) instabilities in the auroral acceleration region. Both the magnetotail and the auroral region are dynamically active and of central importance in the mechanics of the magnetosphere. They are also intimately coupled to each other. Better understanding of the current and particle self- consistencies, acceleration mechanisms, and particle diffusion in the magnetotail and interactions of beams in the auroral zone will lead to an improved global picture of the dynamics of the magnetosphere.

太阳风和地球大气之间的相互作用 磁层负责复杂的耗散 控制近地动力学的过程 环境 对这些过程的研究是 日地研究 等离子体片，它的边界 高纬极光区是极光区的中心 对理解这些过程的重要性。 磁尾等离子体片的存在 从早到晚穿过尾巴的电场意味着 是一个重要的三分之一的颗粒携带 横帆海流 尾巴里的这些粒子 占太阳风携带的总能量的2%， 一个与昼侧磁层的横截面相等的区域， 因此，这是一个重要的，也许是 太阳能风能转移的主要方式 磁层粒子 离子的电流片加速是导致 在等离子体片边界层中发现的不稳定离子束 （PSBL）。 离子和电子粒子的最终运动 人口不仅可能是形成 各向同性等离子体片，但高纬度的潜力 极光区的离散弧结构。 离散的极光弧与向上的 向下沉淀的电子携带的电流， 被加速通过场对准的电位差 10，000伏特。 冷电离层离子被加速向上 相同的电位降。 该赠款由三个项目组成：A）磁尾 颗粒动力学，B）宽带湍流和颗粒扩散 在等离子体片，和C）在极光的不稳定性 加速区 磁尾和极光区 是动态活跃的，在力学中具有核心重要性， 磁层。 它们还与每一个 其他. 更好地理解电流和粒子自- 加速机制和粒子扩散 极光区磁尾和电子束的相互作用 将导致改善全球的动态图片， 磁层