Abstract:
Kn and Ks, the northern and southern hemispheric indices of geomagnetic activity, for the period 1959-1974 are analysed to examine the influence of solar magnetic sector boundary passage. It is shown that hemispheric difference in activity is a function of the type of sector boundary and that greater change is associated with a +/- boundary. Occurrence frequency of the index 0 depicts a significantly larger response in association with a +/- boundary, only for the southern hemisphere index. Ratios of occurrence frequency of Ks to Kn, as a function of sector boundary passage, show significant departures only for indices 0 and 5, indicating two regions of solar wind velocities that cause significant differences in geomagnetic activity of the two hemispheres.
