Prol Fabricio S, Smirnov Artem G, Hoque M Mainul, Shprits Yuri Y
German Aerospace Center (DLR), Institute for Solar-Terrestrial Physics, Neustrelitz, 17235, Germany.
Finnish Geospatial Research Institute (FGI), Department of Navigation and Positioning, National Land Survey of Finland (NLS), Kirkkonummi, 02431, Finland.
Sci Rep. 2022 Jun 13;12(1):9732. doi: 10.1038/s41598-022-13302-1.
In the last years, electron density profile functions characterized by a linear dependence on the scale height showed good results when approximating the topside ionosphere. The performance above 800 km, however, is not yet well investigated. This study investigates the capability of the semi-Epstein functions to represent electron density profiles from the peak height up to 20,000 km. Electron density observations recorded by the Van Allen Probes were used to resolve the scale height dependence in the plasmasphere. It was found that the linear dependence of the scale height in the topside ionosphere cannot be directly used to extrapolate profiles above 800 km. We find that the dependence of scale heights on altitude is quadratic in the plasmasphere. A statistical model of the scale heights is therefore proposed. After combining the topside ionosphere and plasmasphere by a unified model, we have obtained good estimations not only in the profile shapes, but also in the Total Electron Content magnitude and distributions when compared to actual measurements from 2013, 2014, 2016 and 2017. Our investigation shows that Van Allen Probes can be merged to radio-occultation data to properly represent the upper ionosphere and plasmasphere by means of a semi-Epstein function.
在过去几年中，以与标高呈线性依赖关系为特征的电子密度剖面函数在近似电离层顶部时显示出良好的效果。然而，800公里以上的性能尚未得到充分研究。本研究调查了半爱泼斯坦函数表示从峰值高度到20000公里的电子密度剖面的能力。利用范艾伦探测器记录的电子密度观测数据来解析等离子层中标高的依赖性。研究发现，电离层顶部标高的线性依赖关系不能直接用于推断800公里以上的剖面。我们发现，等离子层中标高与高度的依赖关系是二次的。因此，提出了一个标高的统计模型。通过一个统一的模型将电离层顶部和等离子层结合起来后，与2013年、2014年、2016年和2017年的实际测量值相比，我们不仅在剖面形状上，而且在总电子含量的大小和分布上都得到了很好的估计。我们的研究表明，范艾伦探测器可以与无线电掩星数据合并，通过半爱泼斯坦函数恰当地表示上层电离层和等离子层。
