Pignalberi Alessio, Pezzopane Michael, Nava Bruno, Coïsson Pierdavide
Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143, Rome, Italy.
The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste, Italy.
Sci Rep. 2020 Oct 16;10(1):17541. doi: 10.1038/s41598-020-73886-4.
Over the years, an amount of models relying on effective parameters were implemented in the challenging issue of the topside ionosphere description. These models are based on different analytical functions, but all of them depend on a parameter called effective scale height, that is deduced from topside electron density measurements. As their names state, they are effective in reproducing the topside electron density profile only when applied to the analytical function used to derive them. Then, in principle, they do not have any physical meaning. It is the goal of this paper to mathematically link the effective scale height modeled through the Epstein layer to the vertical scale height theoretically deduced from the plasma ambipolar diffusion theory. Firstly, effective and theoretical scale heights are linked through a mathematical relation by showing that they tend to each other in the topside ionosphere. Secondly, their connection is preliminarily demonstrated by calculating effective scale height values from the entire COSMIC/FORMOSAT-3 radio occultation dataset. Thirdly, a possible connection between the vertical gradient of the topside scale height (as obtained by COSMIC/FORMOSAT-3 satellites) and the electron temperature (as obtained by ESA Swarm B satellite) is studied by highlighting corresponding similarities in the diurnal, seasonal, solar activity, and latitudinal variability.
多年来，在描述电离层顶部这一具有挑战性的问题上，已经实现了许多依赖有效参数的模型。这些模型基于不同的解析函数，但它们都依赖于一个称为有效标高的参数，该参数是从电离层顶部电子密度测量中推导出来的。正如其名称所示，它们只有在应用于用于推导它们的解析函数时，才能有效地再现电离层顶部电子密度剖面。因此，原则上它们没有任何物理意义。本文的目标是从数学上把通过爱泼斯坦层模拟的有效标高与从等离子体双极扩散理论理论推导出来的垂直标高联系起来。首先，通过表明它们在电离层顶部相互趋近，有效标高和理论标高通过数学关系联系起来。其次，通过从整个COSMIC/FORMOSAT - 3无线电掩星数据集中计算有效标高值，初步证明了它们之间的联系。第三，通过突出日变化、季节变化、太阳活动和纬度变化方面的相应相似性，研究了电离层顶部标高的垂直梯度（由COSMIC/FORMOSAT - 3卫星获得）与电子温度（由欧空局蜂群B卫星获得）之间可能存在的联系。
