The structure and dynamics of the plasmapause-plasmasphere during July 6-14, 1977 - A study based on whistler data obtained on the ground and data from the ISIS and GEOS-1 spacecraft

Data on the electron density and the position of the plasmapause gained from ground-based whistler detection are augmented by satellite data from a relaxation sensor and a mutual impedance experiment on board the GEOS-1 spacecraft. Additional VHF data were obtained by ISIS satellites. The density profiles measured at close times during magnetic disturbances were identical in the same sectors of the equatorial plane. A radial decrease following a 1/L to the 4th power curve was found in the outward direction after L equals 4. The July 14 event indicated a time delay of the response of the plasmapause to substorms. The July 6 data, obtained during a substorm onset, revealed a regular plasmapause shape until onset, when a pronounced bulge developed in the duskside and plasma elements detached in the early afternoon sector. Trough regions appeared with electron densities of 300/cu cm, compared to 500-550 before the storm.