The characteristics of turbulent plasma in the winter cusp ionosphere is studied based on in-situ data from the Investigation of Cusp Irregularities (ICI) sounding rockets. The electron density fluctuations from ICI-2 and ICI-3 missions have been analyzed for the whole flight, using advanced time-series analysis techniques. The analysis of the autocorrelation scale is indicative of the turbulence integral scale and marks the onset of the turbulent cascade from large to small scales in the power spectrum density of the rocket data. The power spectrum is typical for a turbulent field. The turbulent structures are persistent in the data, which are quantified by analyzing the Probability Distribution Functions (PDFs) and their deviations from the Gaussian distribution. The kurtosis analysis indicates the presence of intermittency. These results are compared with the Local Intermittence Measure - LIM, which confirms the presence of small scale intermittent structures. The turbulence measured by rockets appears well developed and covers frequencies between 1 Hz and several hundred Hz. There is a good agreement with the previous results, suggesting that density fluctuations in the ionospheric cusp agree with the turbulence framework in which intermittent processes transfer energy across different scales.

中文翻译：

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用 ICI 探空火箭研究冬季尖端电离层的湍流和间歇性

基于尖端不规则性调查 (ICI) 探空火箭的现场数据，研究了冬季尖端电离层中湍流等离子体的特性。使用先进的时间序列分析技术，对整个飞行过程中来自 ICI-2 和 ICI-3 任务的电子密度波动进行了分析。自相关尺度的分析表明了湍流积分尺度，并标志着火箭数据功率谱密度中从大到小尺度的湍流级联的开始。功率谱是湍流场的典型特征。湍流结构在数据中持续存在，通过分析概率分布函数 (PDF) 及其与高斯分布的偏差进行量化。峰态分析表明存在间歇性。这些结果与局部间歇性测量 - LIM 进行了比较，后者证实了小规模间歇性结构的存在。火箭测量的湍流看起来很发达，覆盖了 1 Hz 到几百 Hz 的频率。与之前的结果有很好的一致性，表明电离层尖端的密度波动与湍流框架一致，其中间歇过程在不同尺度上传递能量。