We ran the IRAP Plasmasphere Ionosphere Model (IPIM) for several flux tubes at different distances from Earth for very quiet conditions, in order to model the convection and corotation transport of closed flux tubes in the plasmasphere for tilted/eccentric dipolar magnetic field configuration and for solstice and equinox conditions. For each simulation, the model was run for 30 days in order to study the long‐term evolution of the plasmasphere‐ionosphere system. The goal is to study the combined effect of corotation and convection, which causes eventually a lag of the flux tube motion with respect to the Earth. This combination of nonuniform rotation and subcorotation in average becomes important especially in the outer plasmasphere and causes nonuniform drift of the dipole tilt projection in the plane of the flux tube with time, changing drastically the plasma distribution along this flux tube. In the classical representation of the plasmasphere, the ionosphere only depends on angular Magnetic Local Time (MLT) sector. We show that due to the tilt effect, solar illumination along the flux tube and field‐aligned transport varies from one day to the other and causes also a day‐to‐day variation in the plasma distribution along the tube. This effect implies that a stable representation of the plasmasphere in MLT during quiet conditions is an erroneous view, and no real dynamic equilibrium can be reached, in particular close to the stagnation point.

中文翻译：

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用IPIM模拟偶极子倾斜角对电离层等离子体的影响

我们针对非常安静的条件下针对距地球不同距离的多个磁通管运行了IRAP等离子球体电离层模型（IPIM），以对等离子球体在倾斜/偏心偶极磁场配置下的等离子层中对流和同向传输进行建模。冬至和春分条件。对于每个模拟，模型运行30天，以研究等离子体-电离层系统的长期演变。目的是研究同向和对流的综合作用，这最终导致通量管运动相对于地球的滞后。平均而言，这种非均匀旋转和亚同旋转的组合变得尤为重要，尤其是在外部等离子层中，并且会导致偶极子倾斜投影在通量管平面内随时间的不均匀漂移，沿该通量管急剧改变等离子体分布。在等离子层的经典表示中，电离层仅取决于角磁场本地时间（MLT）扇区。我们表明，由于倾斜效应，沿通量管的太阳照度和场对准的运输在一天之间变化，并且还导致沿管的等离子体分布每天发生变化。这种影响意味着在安静条件下MLT中等离子层的稳定表示是一个错误的视图，并且无法达到真正的动态平衡，特别是在停滞点附近。沿通量管的太阳照度和场对准的运输在一天之间是不同的，并且还导致沿该通量管的等离子体分布每天发生变化。这种影响意味着在安静条件下MLT中等离子层的稳定表示是一个错误的视图，并且无法达到真正的动态平衡，特别是在停滞点附近。沿通量管的太阳照度和场对准的传输在一天之间是不同的，并且还导致沿该通量管的等离子体分布每天发生变化。这种影响意味着在安静条件下MLT中等离子层的稳定表示是一个错误的视图，并且无法达到真正的动态平衡，特别是在停滞点附近。