Coincidental TID Production by Tropospheric Weather During the August 2017 Total Solar Eclipse
Coincidental TID Production by Tropospheric Weather During the August 2017 Total Solar Eclipse
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DOI：
10.1029/2018gl080239
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发表时间：
2018-10-28
影响因子：
5.2
通讯作者：
Sivadas, Nithin
中科院分区：
文献类型：
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作者：
Mrak, Sebastijan;Semeter, Joshua;Sivadas, Nithin
已经提出（Chimonas & Hines，1970，https：//doi.org/10.1029/JA075i004p00875）日全食应该产生内部重力波（GW），其表现为电离层高度处的行进电离层扰动（TID）。Zhang et al.（2017，https：//doi.org/10.1002/2017GL076054）最近报告了对最大遮蔽区域的电子密度扰动的观测，声称这些结果是日食引起的弓形波的第一个明确证据。我们提出的证据表明，在连续两天，日食的一天和前一天广泛的TID活动。一个特别强烈的TID同心波场出现在背景电离层5小时前的全食，并持续整个日食。表观中心位于爱荷华州/南达科他州地区，距离日食路径以北300-500 km。TID波参数与雷暴产生的GW/TID的先前观测和模型一致;相反，波参数与日食产生的GW/TID的建模结果相差一个数量级。简明语言摘要最近对2017年日全食当天电离层动力学的研究观察到电离层中的同心波，并将其归因于日食本身。我们提出了一个电离层和对流层天气的并发分析，发现雷暴活动和电离层波场之间有很强的相关性。我们发现，电离层波出现在日食前5小时，他们坚持在一个封闭的空间区域内的整个日食结束。对这些波的仔细分析表明，与以前对对流层天气产生的重力波及其在电离层中作为电离层扰动的印记的研究非常一致。与2017年日全食的模型和其他最近观测结果的进一步比较进一步支持了我们的结论，将电离层波场归因于对流层天气作为驱动机制。总的来说，日食当天的电离层为我们提供了一个有趣的模式，显示了来自太阳和对流层的同时强迫。
It has been proposed (Chimonas & Hines, 1970, https://doi.org/10.1029/JA075i004p00875) that a total solar eclipse should generate internal gravity waves (GWs) that manifest as traveling ionospheric disturbances (TIDs) at ionospheric heights. Zhang et al. (2017, https://doi.org/10.1002/2017GL076054) recently reported observations of electron density perturbations trailing the region of maximum obscuration, claiming the results as the first unambiguous evidences for eclipse-induced bow waves. We present evidence showing extensive TID activity on two consecutive days, the day of the eclipse and the day before. A particularly intense TID concentric wavefield emerged from the background ionosphere 5 hr before the arrival of the totality and persisted there throughout the eclipse. The apparent center was located over Iowa/South Dakota region, 300-500 km north from the eclipse path. We examine concurrent observations of tropospheric and ionospheric weather and find a great spatiotemporal correlation. TID wave parameters do agree with previous observations and models of thunderstorm-generated GWs/TIDs; conversely, the wave parameters are an order of magnitude off from modeling results for eclipse-generated GWs/TIDs.Plain Language Summary Recent studies of ionospheric dynamics on the day of the 2017 total solar eclipse observed concentric waves in the ionosphere and attributed them to the eclipse itself. We present a concurrent analysis of ionospheric and tropospheric weather and find a strong correlation between thunderstorm activity and the ionospheric wavefield. We find that the ionospheric waves emerged 5 hr before the eclipse and they persisted within a confined region of space throughout the end of the eclipse. A careful analysis of these waves shows remarkable agreement with previous studies of tropospheric weather-generated gravity waves and their imprint in the ionosphere as traveling ionospheric disturbances. Further comparison with models and other recent observations of the 2017 total solar eclipse further supports our conclusions to ascribe the ionospheric wavefield to the tropospheric weather as the driving mechanism. In aggregate, the ionosphere on the day of the eclipse provided us with an intriguing pattern, showing simultaneous forcing from the Sun and from the troposphere.