A Synthetical Study of Convection Pattern by Using Results from GEOS-2 S301 and S329 Experiments

Asynthetical study by using the results from the GEOS-2 electron gun experiment S329 and the relaxation sounding experiment S301 is made to discuss the convection pattern in the magnetosphere. The comparison and synthesis are carried out with the help of the Volland's semi-empirical model, which can connect the convection electric field with the shape and dimension of the cold plasma boundary (i. e. the plasmapause). The results of both experiments show a Kp-dependance of the westward rotation of the convection pattern and demonstrate the applicability of the Volland's model in describing the convectionselectric field around the synchronous orbit. The two observations arc contradictory in predicting the size cf the plasma-pause when Kp is high. This is possibly caused by the complexity of the dynamic processes around the plasmapause. The processes concerned and the dawndusk asymmetry of the E-field observed by the electron gun experiment are worthy of further study.