Abstract

Collisions between electrons and neutral molecules are of special interest for the physics of the Earth’s ionosphere, in particular, for determining the ionospheric conductivity and current systems in the lower ionosphere of the planet, as well as elucidating the role they play in attenuating radio waves propagating inside the D and E regions of the ionosphere. The effective collision frequency of electrons can be estimated from laboratory studies of electron mobility in atmospheric gases in combination with rocket measurements of temperature and particle density in the Earth’s upper atmosphere, or it can be determined independently from analysis of radio occultation data. We have developed a method for reconstructing the vertical profiles of the absorption coefficient of decimeter (wavelength ~19 cm) radio waves by solving the inverse problem of signal absorption in the D and E regions of the Earth’s ionosphere. Based on the analysis of radio occultation data from the FORMOSAT-3/COSMIC satellites, the altitude profiles of the absorption coefficient of decimeter (DM) radio waves in the planet’s ionosphere during the geomagnetic storm on June 22–23, 2015, were determined. It is known that the absorption coefficient at a given fixed frequency is directly proportional to both the electron density and the collision frequency of electrons with ions and neutrals. Using the data on the vertical profiles of the absorption coefficient of DM radio waves and the electron density reconstructed from the analysis of FORMOSAT-3/COSMIC radio occultations, we estimated the effective collision frequency of electrons in the D and E regions of the Earth’s high-latitude ionosphere. The practical significance of studying the frequency of electron collisions and the effects of radio wave absorption in the D and E regions of the planet’s ionosphere is associated with maintaining the uninterrupted operation of space radio communication and navigation systems.

中文翻译：

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从射电掩星测量分析确定高纬度电离层E区和D区电子的有效碰撞频率

摘要

电子和中性分子之间的碰撞对于地球电离层的物理学特别重要，特别是对于确定地球电离层下部的电离层电导率和电流系统，以及阐明它们在衰减无线电波传播中所起的作用电离层D区和E区内部。电子的有效碰撞频率可以通过大气气体中电子迁移率的实验室研究结合地球高层大气中温度和粒子密度的火箭测量来估计，或者可以独立于无线电掩星数据的分析来确定。我们开发了一种通过解决地球电离层D和E区域信号吸收的反问题来重建分米（波长~19 cm）无线电波吸收系数垂直剖面的方法。通过对福卫三号/宇宙卫星的射电掩星数据分析，确定了2015年6月22日至23日地磁暴期间地球电离层分米无线电波吸收系数的高度剖面。众所周知，给定固定频率下的吸收系数与电子密度以及电子与离子和中性粒子的碰撞频率成正比。利用Formosat-3 / COSMIC射电掩星分析重建的DM无线电波吸收系数垂直剖面数据和电子密度，估算出地球高压D区和E区电子的有效碰撞频率- 纬度电离层。研究地球电离层D区和E区的电子碰撞频率和无线电波吸收效应的实际意义与维持空间无线电通信和导航系统的不间断运行有关。