The dayside equatorial ionospheric electrodynamics exhibit strong variability driven simultaneously by highly changeable external forcings that originate from the solar extreme ultraviolet (EUV), magnetosphere, and lower atmosphere. We investigate this variability by carrying out comprehensive data‐driven ensemble modeling using a coupled model of the thermosphere and ionosphere, with the focus on the vertical E × B drift variability during a solar minimum and minor storm period. The variability of vertical E × B drift in response to the changes and uncertainty of primary forcings (i.e., solar EUV, high‐latitude plasma convection and auroral particle precipitation, and lower‐atmospheric tide and wave forcing) is investigated by ensemble forcing sensitivity experiments that incorporate data‐driven stochastic perturbations of these forcings into the model. Second, the impact of assimilating FORMOsa SATellite‐3/Constellation Observing System for Meteorology, Ionosphere, and Climate (FORMOSAT‐3/COSMIC) electron density profiles (EDPs) on the reduction of uncertainty of the modeled vertical E × B drift variability resulting from inadequately specified external forcing is revealed. The Communication and Navigation Outage Forecasting System (C/NOFS) ion drift velocity observations are used for validation. The validation results support the importance of the use of a data‐driven forcing perturbation methods in ensemble modeling and data assimilation. In conclusion, the solar EUV dominates the global‐scale day‐to‐day variability, while the lower atmosphere tide and wave forcing is critical to determining the regional variability. The modeled vertical E × B drift is also sensitive to the magnetospheric forcing. The ensemble data assimilation of FORMOSAT‐3/COSMIC EDPs helps to reduce the uncertainty and improves agreement of the modeled vertical E × B drifts with C/NOFS observations.

中文翻译：

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赤道电离层电动力学的数据驱动集合模型：在太阳最低条件下的小暴风雨时期的案例研究

白天的赤道电离层电动力学表现出强烈的可变性，同时受到来自太阳极紫外（EUV），磁层和低层大气的高度可变的外部强迫的驱动。我们通过使用热层和电离层的耦合模型进行综合的数据驱动的集成模型来研究这种变化，重点是在太阳最小和小暴风雨期间的垂直E × B漂移变化。垂直E × B的变异性通过集成强迫敏感度实验研究了响应于主要强迫（例如，太阳EUV，高纬度等离子体对流和极光颗粒降水以及较低大气潮汐和波浪强迫）的变化和不确定性而产生的漂移，该方法结合了数据驱动的随机扰动这些强迫进入模型。其次，将FORMOsa SATellite-3 /星座气象，电离层和气候观测系统（FORMOSAT-3 / COSMIC）电子密度分布图（EDP）同化对减少模拟垂直E × B的不确定性的影响揭示了由于不充分指定的外力导致的漂移变异性。通信和导航中断预测系统（C / NOFS）离子漂移速度观测值用于验证。验证结果支持在集成建模和数据同化中使用数据驱动的强迫摄动方法的重要性。总之，太阳EUV主导着全球范围的日常变化，而较低的大气潮汐和波浪强迫对于确定区域变化至关重要。建模的垂直E × B漂移对磁层强迫也很敏感。FORMOSAT-3 / COSMIC EDP的整体数据同化有助于减少不确定性并提高建模垂直E的一致性×B随C / NOFS观测值漂移。