Thermospheric Neutral Winds Above the Oukaimeden Observatory: Effects of Geomagnetic Activity
Thermospheric Neutral Winds Above the Oukaimeden Observatory: Effects of Geomagnetic Activity
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DOI：
10.1029/2019ja027383
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发表时间：
2020-07
期刊：
影响因子：
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通讯作者：
A. Loutfi;A. Bounhir;F. Pitout;Z. Benkhaldoun;J. Makela
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文献类型：
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作者：
A. Loutfi;A. Bounhir;F. Pitout;Z. Benkhaldoun;J. Makela
在空间天气的背景下，我们研究了2014年至2016年3年间地磁活动对摩洛哥乌凯梅登天文台（地理坐标：北纬31.206°，西经7.866°；磁纬度：北纬22.77°）上空地球热层的影响。该天文台配备了一台法布里 - 珀罗干涉仪（FPI），用于测量热层风速。在这项研究中，确定并分析了41个扰动夜晚（SYM - H≤ - 50纳特，Kp≥5）。我们描述了在平静和扰动条件下，经向风和纬向风的变化以及它们对太阳活动周期的依赖性。我们将风暴期间的经向中性风分为三种变化类型。第一种类型的特征是由行波大气扰动（TAD）引起的环流：第一个TAD来自北方，第二个TAD是越赤道的，来自南方。这种由TAD引起环流的风暴类型占案例的59%。第二种类型在扰动夜晚和平静夜晚的气流之间仅表现出轻微差异。这些案例占案例的33%。第三种类型的特征是整晚都存在越赤道风。这种最后一种类型占案例的8%。最后，我们对FPI数据应用了叠加 epoch分析方法，并且量化了地磁风暴每个阶段对风流和垂直总电子含量（VTEC）的影响。
In the context of space weather, we investigate the effect of geomagnetic activity on Earth's thermosphere above the Oukaimeden Observatory in Morocco (geographic coordinates: 31.206°N, 7.866°W; magnetic latitude: 22.77°N) over 3 years from 2014 to 2016. The observatory is equipped with a Fabry‐Perot interferometer (FPI) that provides measurements of thermospheric wind speed. In this study 41 disturbed nights (with SYM‐H ≤ −50 nT, Kp ≥ 5) were identified and analyzed. We have characterized the meridional and zonal winds variability and dependence on the solar cycle, during both quiet and disturbed conditions. We have classified the storm time meridional neutral winds into three types of variation. The first type is characterized by traveling atmospheric disturbance (TAD)‐induced circulation: the first TAD coming from the north and the second TAD being transequatorial, coming from the south. This type of storm with TAD‐induced circulation accounts for 59% of the cases. The second type exhibits only slight discrepancies between the disturbed and quiet night flows. These cases account for 33% of the cases. The third type is characterized by the transequatorial wind in whole the night. This last type accounts for 8% of the cases. Finally, we apply a superposed epoch analysis method on the FPI data, and the effect of each phase of the geomagnetic storm on the wind flow and vertical total electron content VTEC has been quantified.