Improved characterization and modeling of equatorial plasma depletions
Improved characterization and modeling of equatorial plasma depletions
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DOI：
10.1051/swsc/2018026
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发表时间：
2018-08-22
影响因子：
3.3
通讯作者：
Orus-Perez, Raul
中科院分区：
文献类型：
--
作者：
Blanch, Estefania;Altadill, David;Orus-Perez, Raul
本手稿提出了一种利用从全球导航卫星系统（GNSS）接收器收集的数据来识别赤道等离子体气泡（EPB）出现的方法。该方法采用了先前存在的技术来检测中尺度行进电离层扰动 (MSTID)，其重点是根据 GNSS 信号 (2DTEC) 估计的总电子含量的二阶时间导数。该工具的结果使得对 EPB 的特性进行全面分析成为可能。对EPB发生概率、有效持续时间、消耗深度和总扰动的分析表明，在2002-2014年第23太阳周期下降阶段和第24太阳周期上升阶段，EPB在全球范围内对北纬35度至南35度纬度带内的当地时间和一年中的季节有依赖性。这些结果使得建立一个以太阳通量指数为界的 EPB 模型成为可能，该模型模拟给定季节和当地时间 (LT) 的代表日的 EPB 数量及其特征的概率。模型结果提供了对不同重要方面的深入了解：气泡最多出现在赤道异常波峰附近、半球之间的不对称性以及 EPB 活动增强的首选经度。模型输出与独立观察结果的比较证实了其合理性。
This manuscript presents a method to identify the occurrence of Equatorial Plasma Bubbles (EPBs) with data gathered from receivers of Global Navigation Satellite System (GNSS). This method adapts a previously existing technique to detect Medium Scale Travelling Ionospheric Disturbances (MSTIDs), which focus on the 2nd time derivatives of total electron content estimated from GNSS signals (2DTEC). Results from this tool made possible to develop a comprehensive analysis of the characteristics of EPBs. Analyses of the probability of occurrence, effective time duration, depth of the depletion and total disturbance of the EPBs show their dependence on local time and season of the year at global scale within the latitude belt from 35 degrees N to 35 degrees S for the descending phase of solar cycle 23 and ascending phase of solar cycle 24, 2002-2014. These results made possible to build an EPBs model, bounded with the Solar Flux index, that simulates the probability of the number of EPBs and their characteristics expected for a representative day at given season and local time (LT). The model results provided insight into different important aspects: the maximum occurrence of bubbles take place near the equatorial anomaly crests, asymmetry between hemispheres and preferred longitudes with enhanced EPBs activity. Model output comparisons with independent observations confirmed its soundness.