THE EQUATORIAL ELECTROJET AND THE MAGNETOSPHERE IONOSPHERE COUPLING .2. MODEL STUDY

In order to understand the physics involved in the correlation between the equatorial electroject and magnetosphere-ionosphere coupling, the Senior-Blanc model is expanded for the condition involving the variation of the particle precipitation. A quasi-simulated calculation method is developed to study the potential distribution at middle and low latitudes and the equatorial electrojet when the boundaries or the driving potential changes abruptly. The results indicate a significant effect of the magnetosphere-ionosphere coupling on the equatorial electrojet. It shows that from early morning to midnight, an additional eastward electrojet occurs following the abrupt increase of the driving potential and equatorward expansion of the boundaries concerned. On the other hand, a strong westward equatorial electrojet is developed corresponding to the sudden decrease of the driving source. Many phenomena observed can be explained by the results of model calculation. The discrepancy between the observations of different experiments can be attributed partly to the change of the electrojet pattern at different stages of the process.Astronomy & AstrophysicsSCI(E)6ARTICLE6919-9273