We present an investigation of polar cap plasma structure lifetimes. We analyze both simulated data from ionospheric models (International Reference Ionosphere model and Mass Spectrometer Incoherent Scatter model) and in situ data from the Swarm satellite mission (the 16 Hz Advanced Plasma Density dataset). We find that the theoretical prediction that E‐region conductance is a predictor of F‐region polar cap plasma structure lifetimes is indeed supported by both in situ‐based observations and by ionospheric models. In situ plasma structure lifetimes correlate well with the ratio of F‐ to E‐region conductance. We present explicit predictions of small scale (∼1 km) structure lifetimes, which range from less than 1 h during local summer to around 3 h during local winter. We highlight a large discrepancy between the observational and theoretical scale‐dependency of decay due to diffusion.

中文翻译：

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高纬度等离子体结构的寿命

我们目前对极性帽等离子体结构寿命的调查。我们分析了来自电离层模型（国际参考电离层模型和质谱仪不相干散射模型）的模拟数据以及来自Swarm卫星任务的现场数据（16 Hz高级等离子体密度数据集）。我们发现，原位观测和电离层模型都确实支持了E区电导是F区极性帽等离子体结构寿命的预测因子的理论预测。原位等离子体结构的寿命与F区与E区电导之比密切相关。我们提出了小规模（〜1 km）结构寿命的明确预测，其范围从当地夏季不到1小时到当地冬季3小时左右。