Abstract

Data from ground-based and satellite measurements, as well as the results of numerical modeling of the spatial structure of equatorial ionospheric bubbles, show that the longitude gradients of the logarithm of the electron concentration at the vertical boundaries of the bubbles can reach 10^–3 m^–1. At such electron concentration gradients, the development of drift-dissipative instability is possible. This can generate ionospheric plasma inhomogeneities with spatiotemporal scales characteristic of the equatorial F scatter. This article presents the results of calculations of the increment of the increase in gradient-drift instability on the side walls of ionospheric bubbles obtained on the basis of numerical modeling of the structure of equatorial plasma bubbles and the dispersion equation of drift-dissipative instability. The equatorial plasma bubbles were simulated on the basis of a two-dimensional numerical model of the Rayleigh-Taylor instability in the Earth’s equatorial ionosphere, which is suitable for modeling Rayleigh-Taylor and gradient type inhomogeneities that are strongly elongated along the magnetic field lines. The results of numerical experiments confirm that significant longitudinal plasma gradients at the fronts of the developed equatorial plasma bubble can generate drift-dissipative instability of the ionospheric plasma.

中文翻译：

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赤道等离子气泡前沿的漂移耗散不稳定性增长增量的特征

摘要

来自地面和卫星测量的数据以及赤道电离层气泡空间结构的数值模拟结果表明，气泡垂直边界处电子浓度对数的经度梯度可以达到10 ^–3 m ^–1。在这样的电子浓度梯度下，可能会产生漂移耗散不稳定性。这会产生电离层等离子体不均匀性，其时空尺度是赤道F的特征。分散。本文介绍了基于赤道等离子体气泡结构的数值模拟和漂移耗散不稳定性弥散方程获得的电离层气泡侧壁上梯度漂移不稳定性增加增量的计算结果。基于地球赤道电离层中瑞利-泰勒不稳定性的二维数值模型，对赤道等离子体气泡进行了模拟，该模型适用于模拟沿磁场线强烈拉长的瑞利-泰勒和梯度型不均匀性。数值实验的结果证实，在发展的赤道等离子气泡的前部存在明显的纵向等离子梯度，会产生电离层等离子体的漂移耗散不稳定性。