A fully three-dimensional (3D), time-dependent, MHD interplanetary model has been used, for the first time, to study the relationship between one form of solar activity and transient variations of the north-south component, B-z, of the interplanetary magnetic field (IMF) at 1 AU during the active period of a representative solar cycle. Four cases of initial steady-state solar wind conditions, with different tilt angles of the heliospheric current sheet/plasma sheet (HCS/HPS) which is known to be inclined at solar maximum, are used to study the relationship between the location of solar activity and transient variations of the north-south IMF B-z component at 1 AU. We simulated the initialization of the disturbance as a density pulse at different locations near the solar surface for each case of initial steady-state condition and observed the simulated IMF evolution of B-theta (= -B-z) at 1 AU. The results show that, for a given density pulse, the orientation of the corresponding transient variation of B-z has a strong relationship to the location of the density pulse and the initial conditions of the IMF. A recipe for prediction of the initial B-z turning direction is also presented in this study. In previous studies that used this recipe with only a flat HCS/HPS that was coincident with the solar equatorial plane, we found a prediction accuracy of 83% from a data set of 73 events during solar maximum. The present study that incorporates more realistic HCS/HPS tilt angles confirms the earlier work. Our study leads us to suggest that significant B-z values, associated with substantial post-shock temporal periods of hours at 1 AU, could be achieved if large energies (say, 10(32)-10(33) erg) were released at the Sun in a flare or helmet de-stabilization process.
