Determination of primary electron spectra from incoherent scatter radar measurements of the auroral E region
Determination of primary electron spectra from incoherent scatter radar measurements of the auroral E region
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通过极光 E 区的非相干散射雷达测量确定一次电子能谱
DOI：
10.1029/2004rs003042
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发表时间：
2005
期刊：
影响因子：
1.6
通讯作者：
F. Kamalabadi
中科院分区：
文献类型：
--
作者：
J. Semeter;F. Kamalabadi
本文介绍了一种利用非相干散射雷达（ISR）反演极光电离层的方法，以确定入射电子的能谱。构建了一个将电子微分数通量与离子体积产生率联系起来的线性模型，后者使用连续性方程从测量的电子密度分布中推导出来。使用最大熵方法（MEM）反演正演模型。ISR反演的这种实现被认为是非常强大的模型和测量不确定性的主要来源。该程序被应用于高分辨率测量（1.2 s × 1 km）的Sondrestrom ISR记录在极光浪涌。在恢复的光谱散装等离子体特性的分析表明，特征能量和净数通量之间的关系是高度非线性的极光浪涌的发病过程中，观察，现在可以进行统计评估。这种对极光加速区时间行为的看法无法通过星载测量获得;因此ISR反演构成了解决磁层和电离层随时间变化的耦合的关键工具。
A technique is presented for inverting incoherent scatter radar (ISR) measurements of the auroral ionosphere to determine the incident electron energy spectrum. A linear model is constructed relating electron differential number flux to the volume production rate of ions, the latter derived from measured electron density profiles using a continuity equation. The forward model is inverted using the maximum entropy method (MEM). This implementation of ISR inversion was found to be remarkably robust to the principal sources of model and measurement uncertainty. The procedure was applied to high‐resolution measurements (1.2 s × 1 km) by the Sondrestrom ISR recorded during an auroral surge. Analysis of bulk plasma properties in the recovered spectra suggested that the relationship between the characteristic energy and the net number flux was highly nonlinear during the onset of the auroral surge, an observation that can now be evaluated statistically. This perspective on the temporal behavior of the auroral acceleration region cannot be accessed through spaceborne measurements; ISR inversion thus constitutes a critical tool for addressing time‐dependent coupling of the magnetosphere and ionosphere.