M-I Coupling: Global Scale Imaging of High Latitude Poynting Flux

研究人员将使用一种新技术，从电场E与磁扰动强度b的叉积直接评估坡印亭通量的全球尺度分布。能量从磁层传输到电离层的主要方式是通过高纬度极区的坡印亭通量和粒子降水。尽管坡印亭通量提供了更多的能量，但它的特征是最不好的。除了长期的统计研究外，对高纬度电离层电磁能量沉积的全球分布的评估取决于电离层电导率的统计模型。研究中的磁扰动取自Irdium工程磁强计数据，电场取自SuperDARN系统的相干电离层散射雷达。通过这种方法，研究人员将在大约1小时的时间尺度上直接评估全球尺度的坡印亭通量，纬度分辨率为2，经度分辨率为2小时。这项工作的主要科学目标是描述高纬度Pointing通量在大尺度磁层-电离层耦合中的作用。到目前为止的结果表明，坡印亭通量的区域在不同的情况下有很大的不同，可能反映了外加太阳风条件的影响。最强的坡印亭通量通常集中在极光纬度地区。此外，极冠上的净坡印亭通量约占总通量的三分之一。这些结果提出了几个将予以解决的问题。为此，研究人员将(1)确定电磁能通量和粒子能通量之间的分配；(2)确定热层对强Poynting通量区域的响应；(3)将Poynting通量的全球分布与现场卫星测定和非相干散射雷达结果进行比较；以及(4)调查中性风发电机的影响。这项研究将涉及与其他研究人员的合作研究。与使用其他资产，特别是非相干散射雷达获得的信息技术动态结果进行比较，是这项研究的一个组成部分。另一个重要因素是，将使用Iridium/SuperDARN数据得出的产品与其他技术进行相互比较，包括对DMSP卫星的Poynting通量的现场估计，以及对热层属性和来自包括非相干散射雷达在内的其他来源的热层/电离层反应的较小规模估计。

The investigators will use a new technique to evaluate the global-scale distribution of Poynting flux directly from the cross product of the electric field, E, with the magnetic perturbation intensity, b. The principal means by which energy is transported from the magnetosphere to the ionosphere is by Poynting flux and particle precipitation in the high latitude polar regions. Although the Poynting flux accounts for more energy, it is the least well characterized. Except for long-term statistical studies, evaluations of the global distribution of electromagnetic energy deposition in the high latitude ionosphere depend on statistical models of ionospheric conductivity. The magnetic perturbations in this study are derived from Iridium engineering magnetometer data and the electric field is derived from coherent ionospheric scatter radars of the SuperDARN system. By this method, the investigators will evaluate the global scale Poynting flux directly on time scales of about one hour with a resolution of 2 in latitude and two hours in longitude. The overarching scientific goal of this work is to characterize the role of high latitude Poynting flux in large-scale magnetosphere-ionosphere coupling. Results to date indicate that the regions of Poynting flux vary dramatically from case to case, possibly reflecting the influence of imposed solar wind conditions. The most intense Poynting flux is often concentrated in zones at auroral latitudes. In addition, the net Poynting flux over the polar cap accounts for roughly one third of the total. These results pose several issues that will be addressed. To accomplish this, the investigators will (1) Determine the partitioning of energy flux between electromagnetic and particle energy flux; (2) Identify thermospheric responses to regions of intense Poynting flux; (3) Compare the global distributions of Poynting flux with in-situ satellite determinations and incoherent scatter radar results; and (4) Investigate the influence of the neutral wind dynamo. The study will involve collaborative studies with other researchers. Comparison with results on IT dynamics obtained using other assets, particularly incoherent scatter radars is an integral component of the research. Another important element is the inter-comparison of products derived with the Iridium/SuperDARN data with other techniques including in-situ estimates of Poynting flux from DMSP satellites and smaller scale estimates of thermospheric properties and thermosphere/ionosphere response from other resources including incoherent scatter radars.