等离子体层及其Plume区的电子加热的特性研究

The stable auroral red (SAR)arcs is an unique feature in the sub-auroral ionosphere. The physical mechanism of generating the SAR arcs is an unsolved project and becomes a key research of the space physics at sub-auroral latitudes.The project focus on the physical mechanism of heating the electrons in the plasmasphere and plumes and its response for the kp index and the solar wind pressure, as well as the spatial propagating characteristic of heating flux caused by the heated electrons from the magnetosphere into the ionosphere. Through an analysis of the waves and distributions of heating electrons with observations of the Cluster satellites, The physical mechanism of heating electrons in the plasmasphere and plume can be revealed, i.e,the Coulomb collision interactions or resonant Laudau damping of EMIC waves. With the electron temperature observed by the DMSP satellite, the relationship of the electron heating with the kp index and solar wind pressure can be obtained in order to find the dependence of the electron heating on the the magnetospheric activity and the solar wind pressure. Finally, with conjoint observations of the Cluster and DMSP satellites,the spatial propagating characteristic of heating flux caused by the heated electrons from the magnetosphere into the ionosphere can be obtained. Those research are very important to reveal the physical mechanism of generating the SAR arcs at sub-auroral latitudes, as well as the energy coupling in the system of the plasmasphere-RC-ionosphere.

亚极光区稳定的极光红弧（SAR）是亚极光区独特的空间物理现象。其产生机制仍然是当今空间物理悬而未决的难点及热点问题。本项目以等离子体层及Plume区电子的加热机制、电子的加热对太阳风条件的响应特性、以及由电子加热形成热流从磁层到电离层的传输空间特性为主要的研究内容。通过Cluster观测数据的波动分析及加热后电子的分布特征，揭示EMIC波朗道共振或库仑碰撞相互作用对等离子体层及Plume区冷电子的加热特性。利用DMSP卫星的电子温度的观测数据，统计分析电子温度增加随kp指数、太阳风动压间的关系，从而揭示太阳风动压及磁层的暴时活动对等离子体层冷电子加热的影响。利用Cluster和DMSP卫星的电子加热的联合观测，揭示等离子体层及Plume区时的冷电子加热形成的热流从磁层到电离层传输的空间特性。研究结果有助于揭示亚极光区平稳极光红弧的产生机制及等离子体层-环电流-电离层的能量耦合特征。

亚极光区稳定的极光红弧（SAR）是亚极光区独特的空间物理现象。其产生机制仍然是当今空间物理悬而未决的难点及热点问题。内磁层波粒相互作用导致的等离子体层及Plume区冷电子的加热是产生SAR的主要机制。本项目利用卫星与地面的联合观测，研究了内磁层等离子体波对等离子体层电子的加热机制、内磁层等离子体波的空间分布、波粒相互作用导致的电离层效应。本研究项目取得了一系列突出的研究成果：获得了等离子体层Plume中EMIC波加热冷电子的观测证据及加热源区，揭示了产生亚极光区稳定的极光红弧的物理机制。获得了等离子体层内结构化电场对等离子体层冷电子加热的观测证据，从而提出了等离子体层冷电子加热的新机制。获得等离子体层中EMIC波的空间分布及其散射辐射带电子对太阳活动的响应特征。首次在等离子体层顶外偏离磁赤道处发现了氧离子回旋谐波，获得了氧离子回旋谐波的波动特征。首次在等离子体层顶发现了热氦离子对平行传播的EMIC波的调制。首次报道了背景电子密度对磁声波幅度调制的实地观测证据，揭示了背景电子密度对磁声波幅度调制的物理机制。首次报道了磁声波对等离子体层冷等离子体加热的实地观测证据，揭示了磁声波加热冷等离子体的物理机制。系统地揭示了来源于电离层的氧离子对内磁层EMIC波激发的调制。揭示了来源于太阳风的He++离子对内磁层EMIC波激发的调制。获得了内磁层中沉降环电流粒子的电离层效应以及对无线电波传播的影响。研究成果多次被国际权威杂志《JGR》、《GRL》等引用。以上研究结果对揭示内磁层-电离层系统的物质及能量的耦合特征具有重要的意义。