Whistler observations of the dynamical behavior of the plasmapause during June 17--22, 1973

The dynamical behavior of the plasmapause is studied using whistlers recorded at Siple, Antarctica (approx.84degreeW, Lapprox.4) during June 17--22, 1973. The magnetic activity during this period remained fairly disturbed until June 21, causing the plasmapause to contract to less than 3 earth radii (R/sub E/). Sudden quieting on June 22 caused the plasmasphere to develop complex outlying structures with the high density region extending out to about 6 R/sub E/. The plasmapause data show a repeated diurnal pattern of a relatively slow decrease in equatorial radius by approx.0.5--1 R/sub E/ during the night and a more rapid increase by about the same amount near dusk when the plasmasphere bulge is encountered. These data should provide a basis for detailed correlative studies of many plasmapause-associated phenomena