GEM: Evolution of Plasmasphere, Plumes and Fine Structure

该奖项由2009年美国复苏和再投资法案（公法111 - 5）资助。该项目将收集来自5个不同卫星任务（OGO-5，ISEE-1，CRRES，Polar和IMAGE）的等离子体密度测量数据库。这两个任务有互补的轨道，跨越大约4个太阳周期。等离子体磁层的侵蚀和恢复周期取决于磁层强度的相对变化以及对流最后一次大变化的时间。因此，本项目将采用叠加历元时间分析。将使用自动算法识别从轻度到严重干扰的对流事件，并将为所有数据分配历元时间。该项目将创建一个全球等离子体层密度经验模型，其中包括羽流和精细尺度结构，并通过空间、选定的地磁指数、历元时间、太阳黑子数量和季节进行参数化。精细结构分析将通过从全球尺度分布中分离尺寸低于预定义长度尺度的密度特征来进行。然后，精细结构将通过其对模型中使用的各种参数的依赖性来表征。将模型结果与从LANL和DMSP航天器（模型创建中未使用的两个任务）获得的数量密度进行比较，以验证模型。该模型将与5-使命数据库中的具体案例研究一起沿着使用，以检查等离子体层羽流的随时间变化的形态、侵蚀等离子体的昼侧运输的细节以及运输过程中产生的细尺度结构。等离子体层羽流可以减缓昼侧重联率（调制整个磁层的能量输入）。此外，全球的密度分布，和精细结构，普遍存在于整个plasmasspectrometer施加一个显着的影响后的增长，传播和有效性的波散射高能粒子。所有结果将公布并发布到GEM Wiki网站，以及西南研究所主办的镜像网站。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This project will assemble a database of number density measurements in the plasmasphere from 5 different satellite missions (OGO-5, ISEE-1, CRRES, Polar, and IMAGE). The missions had complementary orbits and spanned roughly 4 solar cycles. The cycle of erosion and recovery of the plasmasphere depends on the relative changes of the strength of magnetospheric as well as on the time since the last major change in convection. Therefore, this project will employ a superposed epoch time analysis. Convection events ranging from mild to severely disturbed will be identified using an automated algorithm and epoch times will be assigned to all data. The project will create a global empirical model of plasmaspheric density that includes both plumes and fine-scale structure, parameterized by space, selected geomagnetic indices, epoch time, sunspot number, and season. Fine structure analysis will be done by isolating from the global-scale distribution those density features whose size falls below a pre-defined length scale. The fine structure will then be characterized by its dependences on the various parameters being used in the model. Comparisons of the model results with number densities obtained from LANL and DMSP spacecraft (two missions not used in the models creation) will be used to validate the model. This model will be used along with specific case studies from the 5-mission database to examine the time-dependent morphology of plasmaspheric plumes, the details of dayside transport of the eroded plasma, and the fine-scale structures that are created during the transport. Plasmaspheric plumes can slow down the dayside reconnection rate (modulating the energy input to the entire magnetosphere). In addition, the global density distribution, and the fine structure that prevails throughout the plasmasphere exert a significant influence upon the growth, propagation, and effectiveness of waves that scatter energetic particles. All results will be published and posted to the GEM Wiki website, and to a mirror site hosted by Southwest Research Institute.