Investigation of the causes of the longitudinal variation of the electron density in the Weddell Sea Anomaly
Investigation of the causes of the longitudinal variation of the electron density in the Weddell Sea Anomaly
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DOI：
10.1002/2016ja023565
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发表时间：
2017-06
期刊：
影响因子：
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通讯作者：
P. Richards;R. Meier;Shih‐Ping Chen;D. Drob;P. Dandenault
中科院分区：
文献类型：
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作者：
P. Richards;R. Meier;Shih‐Ping Chen;D. Drob;P. Dandenault
本文调查并量化了威德尔海异常（WSA）的原因，这是南美洲尖端附近的一个区域，在2007年至2010年太阳活动最小的时候，大约从西经30°至120°，南纬50°至75°。这个区域是不寻常的，因为午夜峰值电子密度超过中午峰值电子密度在夏季。这项研究比以前的研究更加定量，因为与其他模型不同，它吸收了选定的数据参数来约束物理模型，以便调查数据的其他方面。结果表明，普遍接受的WSA与磁场磁偏角和中性风倾斜效应有关的解释并不能解释电子密度的纵向变化。相反，中性风和中性密度的纵向变化是WSA最可能的解释。这些纵向风和密度的变化是由于不同的纬度距离极光区的能量输入。不需要等离子体质谱仪或其他来源的贡献。此外，它表明，一个广泛使用的经验热层密度模型高估的纵向变化在西撒哈拉地区。
This paper investigates and quantifies the causes of the Weddell Sea Anomaly (WSA), a region near the tip of South America extending from approximately 30° to 120°W geographic longitude and 50° to 75°S geographic latitude at solar minimum between 2007 and 2010. This region is unusual because the midnight peak electron density exceeds the midday peak electron density in summer. This study is far more quantitative than previous studies because, unlike other models, it assimilates selected data parameters to constrain a physical model in order to investigate other aspects of the data. It is shown that the commonly accepted explanation that the WSA is related to the magnetic field declination and inclination effects on the neutral wind does not explain the longitudinal variation of the electron density. Rather, longitudinal changes in the neutral winds and neutral densities are the most likely explanation for the WSA. These longitudinal wind and density changes are attributed to the varying latitudinal distance from the auroral zone energy input. No contributions from the plasmasphere or other sources are required. Furthermore, it is shown that a widely used empirical thermosphere density model overestimates the longitudinal changes in the WSA region.