Correlation between interplanetary sector structure and radio propagation quality

The behavior of the radio propagation quality index, Q, and of the geomagnetic activity index, Kp, with respect to sector boundaries during 1968 is analyzed. The superposed epoch analysis performed for these parameters with respect to 33 sector boundaries reveals that, on an average, the Q index falls across the boundaries and the Kp index rises at the sector boundaries. The close anticorrelation found between the variations of Q and Kp indices with respect to sector boundaries might suggest that both radio propagation and geomagnetic disturbances are accounted for by the same magnetospheric and ionospheric modifications, related to sector boundaries. Hence, the interplanetary sector structure seems to influence indirectly the state of the ionosphere.