Large Scale High-Latitude Ionospheric Electrodynamic Fields and Currents
Large Scale High-Latitude Ionospheric Electrodynamic Fields and Currents
复制标题
大规模高纬度电离层电动力场和电流
DOI：
10.1007/s11214-016-0269-9
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发表时间：
2017
影响因子：
10.3
通讯作者：
G. Lu
中科院分区：
文献类型：
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作者：
G. Lu
本文对电离层电动力学同化映射（AMIE）方法进行了概述并介绍了其应用。AMIE综合了来自各种地基和天基仪器的观测结果，以同时推导出电离层电导率、电场、电离层等效电流、水平电流、场向电流以及其他相关电动力学场的全球模式。文中给出了一些例子来说明不同数据输入对AMIE输出的影响。由地面磁强计数据推导出的AMIE模式通常与由卫星磁强计数据推导出的模式相似。但是地面磁强计数据得出的极区跨越电位降比卫星磁强计数据得出的要小约15 - 45%。与原位卫星磁强计数据相比，地面磁强计也大大低估了空间中的磁扰动。然而，当使用卫星磁强计数据时，AMIE能够以17 - 21%的平均均方根（RMS）误差重现沿卫星轨道观测到的磁扰动。除了推导电离层电动力学场的瞬时状态外，AMIE的用途还可以很容易地扩展到获取这些场的平均分布及其相关的变异性。这些信息对于“蜂群”（Swarm）观测的分析和解释应该是有价值的。
This paper provides an overview as well as the application of the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure. AMIE synthesizes observations from various ground-based and space-born instruments to derive global patterns of ionospheric conductance, electric fields, ionospheric equivalent current, horizontal currents, field-aligned currents, and other related electrodynamic fields simultaneously. Examples are presented to illustrate the effects of the different data inputs on the AMIE outputs. The AMIE patterns derived from ground magnetometer data are generally similar to those derived from satellite magnetometer data. But ground magnetometer data yield a cross-polar potential drop that is about 15–45 % smaller than that derived from satellite magnetometer data. Ground magnetometers also grossly underestimate the magnetic perturbations in space when compared with the in situ satellite magnetometer data. However, when satellite magnetometer data are employed, AMIE is able to replicate the observed magnetic perturbations along the satellite tracks with a mean root-mean-square (RMS) error of 17–21 %. In addition to derive snapshots of ionospheric electrodynamic fields, the utility of AMIE can be easily expanded to obtain the average distributions of these fields along with their associated variability. Such information should be valuable to the analysis and interpretation of the Swarm observations.