Dynamics of the Dayside Magnetosphere

这项拨款的先前工作集中在白天磁层的动力学上，这是由动力学探索者1号航天器上的等离子体测量确定的。这项研究的主要重点是太阳风等离子体通过极尖的注入及其随后在磁层内的传输。新的工作将继续集中在这一领域，主要使用来自动力探索者1号航天器的数据，但也使用来自Isee-1、Isee-3、AMPTE、EISCAT以及南极洲、阿拉斯加和斯堪的纳维亚地面站的相关数据。此外，重要的工作将用于研究低纬度边界层到中纬度的映射以及离子和电子在白天的平行和横向加速。在研究磁鞘与电离层的相互作用时，将引入一个重要的新现象——通量传递事件（FTE）。FTE的中纬度特征，称为重连通量管（RFT），将与磁层顶FTE和电离层中FTE效应的地面特征相关联。对极尖下FTE的地面特征的确认将提供大量的FTE观测资料，这些资料可用于研究低纬度边界层的流动行为。这项工作的重要性在于认识到FTE代表了磁层磁能的主要来源。航天器数据已经被用来识别FTE，现在这项工作将使用地面数据来调查电离层特征。这是地球空间环境建模（GEM）的目标之一，因此，这项工作可以被视为GEM的先驱。

Previous work on this grant has concentrated on the dynamics of the dayside magnetosphere as determined from plasma measurements made on the Dynamics Explorer 1 spacecraft. The area of prime emphasis in this research has been the injection of solar-wind plasma through the polar cusp and its subsequent transport within the magnetosphere. The new work will continue to focus on this area primarily using data from the Dynamics Explorer 1 spacecraft, but with correlative data from Isee-1, Isee-3, AMPTE, EISCAT, and ground stations in Antarctica, Alaska, and Scandinavia. In addition, significant effort will go toward the study of the mapping of the low-latitude boundary layer to midaltitudes and of the dayside parallel and transverse acceleration of ions and electrons. An important new phenomenon, the flux transfer event (FTE) will be introduced in studying the interactions of the magnetosheath with the ionosphere. Midaltitude signatures of FTE's, called reconnected flux tubes (RFT's), will be correlated with magnetopause FTE's and ground signatures of FTE effects in the ionosphere. Confirmation of ground signatures of FTE's under the polar cusps will make available a vast set of FTE observations that can be used to study the behavior of flows in the low-latitude boundary layer. The importance of this work resides in the recognition that FTE's represent a major source of magnetic energy for the magnetosphere. Spacecraft data have been used to identify FTE's and now this work will use ground based data to investigate ionosphere signatures. This is one of the objectives of Geospace Environment Modelling (GEM) and, therefore, this work can be regarded as a forerunner to GEM.