Tidal and Planetary Wave (PWs) amplitudes are strongly influenced by Sudden Stratospheric Warming (SSW) events. A nonlinear interaction between the tidal winds and planetary waves during the SSW may contribute to the intensification of sporadic-E () layers in the lower thermosphere. This work investigated the relationship between SSW events in the Northern Hemisphere and the layer occurrence at low latitudes in the Brazilian sector. We used data from digital ionosondes installed in the observatories of Araguatins (ARA, 5.65° S; 48.12° W; dip lat. −5.44°) and São José dos Campos (SJC, 23.18° S; 45.89° W; dip lat. −21.37°) to analyze the layers. Additionally, we used the temperature, zonal wind, and PWs data at high latitudes in the Northern Hemisphere during the major SSW event that occurred in February/2018 and during the events of Dec/2018–Jan/2019 and Dec/2020–Jan/2021. The results showed a maximum frequency peak of 20 MHz (∼5 × 10 electrons.cm) at ARA and SJC during these SSW events. The large values of , , and electronic densities were observed between 100 and 115 km height in the type layers during daytime or nighttime periods. The results also showed that the number of large values of , , and electronic density of the layer was much higher in ARA than in SJC, in general. The wavelet power spectrum analyses of the and showed a periodicity of 2-days before and after the central day of the SSWs events at the station of ARA, with three prominent peaks in the 2018/2019 event. At the SJC station the quasi-2-day periodicity in the wavelet analyses of the was observed after the central day in all three SSW events, with a peak before the central day during the 2020/2021 event.

中文翻译：

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北半球平流层突然变暖对巴西扇区零星E层的影响

潮汐和行星波 (PW) 振幅受到平流层突然变暖 (SSW) 事件的强烈影响。 SSW期间潮汐风和行星波之间的非线性相互作用可能有助于低层热层中零星-E()层的强化。这项工作调查了北半球SSW事件与巴西地区低纬度层发生之间的关系。我们使用了安装在阿拉瓜廷斯（ARA，南纬 5.65°；西经 48.12°；纬度 -5.44°）和圣若泽多斯坎波斯（SJC，南纬 23.18°；西经 45.89°；纬度 -5.44°）天文台的数字电离探空仪的数据。 21.37°）来分析各层。此外，我们还使用了 2018 年 2 月发生的主要 SSW 事件期间以及 2018 年 12 月至 2019 年 1 月和 2020 年 12 月至 1 月事件期间北半球高纬度地区的温度、纬向风和 PW 数据。 2021 年。结果显示，在这些 SSW 事件期间，ARA 和 SJC 的最大频率峰值为 20 MHz（∼5 × 10 electronics.cm）。在白天或夜间期间，在 100 至 115 km 高度之间的类型层中观察到较大的 、 和 电子密度值。结果还表明，一般来说，ARA 中的 、 和 电子密度大值的数量比 SJC 中的要高得多。小波功率谱分析显示ARA台站SSWs事件中心日前后各有2天的周期性，其中2018/2019年事件出现了3个显着峰值。在 SJC 站，在所有三个 SSW 事件的中心日之后观察到小波分析的准 2 天周期性，并在 2020/2021 事件期间在中心日之前出现峰值。