In this work, we carry out a comprehensive modeling study, using the Thermosphere–Ionosphere–Electrodynamics General Circulation Model, to explore the physical processes by which the longitude‐dependent geomagnetic field drives the longitudinal variations of the sunrise enhancement of the zonal electric fields at the dip equator near the June solstice. Numerical experiments and diagnostic analyses of the electrodynamics equation show that the longitudinal differences of the equatorial zonal electric fields near sunrise are primarily associated with the longitudinal variations in the zonal wind dynamo, with those from the meridional wind dynamo contributing secondarily. Furthermore, the longitudinal differences of the wind dynamo near sunrise are mainly related to the longitudinal variations of and conductance, which are caused primarily by the direct influence of the longitudinal structures of magnetic field declination and strength. Meanwhile, the longitudinal variations of neutral winds, which also result in moderate longitudinal variations, play a secondary role in the longitudinal variations of the neutral wind dynamo, while plasma density, which has minor longitudinal differences near sunrise, contributes slightly by modifying the conductance. Overall, the sunrise enhancement in June is more significant at the longitudes where the magnetic field strength and distortion are larger or the magnetic field declination is smaller in the Northern Hemisphere.

中文翻译：

---

日出附近赤道电离层电场的纵向变化

在这项工作中，我们使用热层-电离层-电动力学通用环流模型进行了全面的建模研究，以探索物理过程，其中依赖于经度的地磁场驱动纬向电场的日出增强的纵向变化。六月冬至附近的赤道。电动力学方程的数值实验和诊断分析表明，日出附近的赤道纬向电场的纵向差异主要与纬向风发电机的纵向变化有关，其次是经向风发电机的纵向变化。此外，日出前后风发电机的纵向差异主要与风的纵向变化有关。和电导，这主要是由磁场偏角和强度的纵向结构的直接影响引起的。同时，中性风的纵向变化也会导致适度的纵向变化，在中性风发电机的纵向变化中起次要作用，而在日出附近具有较小纵向差异的等离子体密度则通过改变电导而略有贡献。总体而言，在北半球，磁场强度和畸变较大或磁场偏角较小的经度，6月的日出增强作用更为明显。