Abstract Available manually scaled foF2 observations over 50 years on Juliusruh, 33 years on Slough, and 37 years on Rome stations were used to check the association between quiet-time foF2 disturbances (Q-disturbances) and following on isolated magnetic storms. Of course, such cases exist, however Pearson's contingency coefficient, Chi-square and Odds ratio tests applied to check a measure of association gave the absence of relationship even at the 95% confidence level. The lack of association makes it impossible to use F2-layer disturbances as precursors for magnetic storms. The observed cases of apparent relationship between two events should be considered as random and physically unconditioned. The published cases indicating the relationship between two events can be explained in the framework of regular F2-layer variations not related by any means to the following on magnetic storms. Plain language summary The Earth's upper atmosphere, including the ionosphere, is under total solar control – direct or indirect. F2-layer disturbances occurring during magnetically disturbed periods are due to these magnetic disturbances and they are not discussed in the paper. However there are quiet-time F2-layer disturbances (Q-disturbances) occurring under low and very low level of geomagnetic activity. The relationship of such Q-disturbances with following on isolated magnetic storms is analyzed in the paper. All available manually scaled hourly foF2 observations on Juliusruh (50 years), on Rome (37 years), and Slough (33 years) have been analyzed to estimate a measure of association between two binary variables: F2-layer Q-disturbances and isolated magnetic storms. Pearson's contingency coefficient, Chi-square and Odds ratio tests applied to check a measure of association gave the absence of relationship even at the 95% confidence level. This is an expected result as from physical point of view such relationship has no physical explanation. The lack of association makes it impossible to use foF2-layer disturbances as precursors for magnetic storms – the idea being discussed in the literature. The observed cases of apparent relationship between two events should be considered as random and physically unconditioned. The published cases indicating the relationship between two events can be explained in the framework of regular F2-layer variations not related by any means to the following on magnetic storms.

中文翻译：

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中纬度风暴前 F2 层 Q 扰动：它们存在吗？

摘要 使用 Juliusruh 50 年、Slough 33 年和罗马站 37 年的可用手动缩放 foF2 观测来检查安静时间 foF2 扰动（Q 扰动）与孤立磁暴跟踪之间的关联。当然，这种情况是存在的，但是，即使在 95% 的置信水平下，用于检查关联度量的 Pearson 权变系数、卡方和优势比检验也给出了不存在关系。缺乏关联使得无法将 F2 层扰动用作磁暴的前兆。观察到的两个事件之间明显关系的案例应被视为随机和物理无条件的。已发表的表明两个事件之间关系的案例可以在与以下磁暴没有任何关系的规则 F2 层变化框架中进行解释。简单的语言总结 地球的高层大气，包括电离层，完全受太阳控制——直接或间接。磁扰期间发生的F2层扰动是由这些磁扰引起的，本文未对其进行讨论。然而，在低和非常低的地磁活动水平下，会发生静止时间 F2 层扰动（Q 扰动）。论文分析了这种Q-扰动与跟踪孤立磁暴的关系。Juliusruh（50 年）、罗马（37 年）、和 Slough（33 年）已经被分析来估计两个二元变量之间的关联度量：F2 层 Q 扰动和孤立的磁暴。即使在 95% 的置信水平下，用于检查关联度量的 Pearson 权变系数、卡方和优势比测试也表明不存在关系。这是预期的结果，因为从物理角度来看，这种关系没有物理解释。缺乏关联使得不可能使用 foF2 层扰动作为磁暴的前兆——这个想法在文献中被讨论过。观察到的两个事件之间明显关系的案例应被视为随机和物理无条件的。