Abstract. In the emerging ionosphere–space–weather paradigm, investigating the dynamical properties of ionospheric plasma irregularities using advanced computational nonlinear algorithms provide new insights into their turbulent-seeming nature, for instance, the evidence of energy distribution via a multiplicative cascade. In this study, we present a multifractal analysis of the equatorial F region in situ data obtained from two different experiments performed at Alcântara (2.4 ∘ S, 44.4 ∘ W), Brazil, to explore their scaling structures. The first experiment observed several medium- to large-scale plasma bubbles whereas the second experiment observed vertical uplift of the base of the F region. The multifractal detrended fluctuation analysis and the p -model fit are used to analyze the plasma density fluctuation time series. The result shows the presence of multifractality with degree of multifractality 0.53–0.93 and 0.3 ≤ p ≤ 0.4 cascading probability for the first experiment. Other experimental data also exhibit multifractality with degree of multifractality 0.19–0.27 and 0.42 ≤ p ≤ 0.44 cascading probability in ionospheric plasma irregularities. Our results confirm the nonhomogeneous nature of plasma irregularities and characterize the underlying nonhomogeneous multiplicative cascade hypothesis in the ionospheric medium. Differences in terms of scaling and complexity in the data belonging to different types of phenomena are also addressed.

中文翻译：

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多重分形背景下赤道 F 区等离子体不规则性的结构表征

摘要。在新兴的电离层 - 空间 - 天气范式中，使用高级计算非线性算法研究电离层等离子体不规则性的动力学特性提供了对其看似湍流的性质的新见解，例如，通过乘法级联进行能量分布的证据。在这项研究中，我们对从在巴西阿尔坎塔拉 (2.4 ∘ S, 44.4 ∘ W) 进行的两个不同实验中获得的赤道 F 区原位数据进行多重分形分析，以探索它们的标度结构。第一个实验观察到几个中到大尺度的等离子体气泡，而第二个实验观察到 F 区底部的垂直隆起。多重分形去趋势波动分析和p模型拟合用于分析等离子体密度波动时间序列。结果表明存在多重分形，多重分形度为 0.53–0.93，第一个实验的级联概率为 0.3 ≤ p ≤ 0.4。其他实验数据也表现出多重分形，其多重分形度为 0.19–0.27 和 0.42 ≤ p ≤ 0.44 在电离层等离子体不规则性中的级联概率。我们的结果证实了等离子体不规则性的非均匀性，并表征了电离层介质中潜在的非均匀乘性级联假设。还解决了属于不同类型现象的数据在缩放和复杂性方面的差异。27 和 0.42 ≤ p ≤ 0.44 电离层等离子体不规则性的级联概率。我们的结果证实了等离子体不规则性的非均匀性，并表征了电离层介质中潜在的非均匀乘性级联假设。还解决了属于不同类型现象的数据在缩放和复杂性方面的差异。27 和 0.42 ≤ p ≤ 0.44 电离层等离子体不规则性的级联概率。我们的结果证实了等离子体不规则性的非均匀性，并表征了电离层介质中潜在的非均匀乘性级联假设。还解决了属于不同类型现象的数据在缩放和复杂性方面的差异。