Dynamic MHD modeling of the solar wind disturbances during during the August 1972 events

A time-dependent one-dimensional MHD theoretical model (Steinolfson et al., 1975) is tested by using plasma and magnetic field observations of Pioneer 9 and Pioneer 10 during the August 1972 events on the Sun and the interplanetary medium. The observations of Pioneer 9 at 0.78 AU were used as `input' for the theoretical model. The plasma and magnetic field forcing functions were superimposed upon a preexisting ambient solar wind at this inner boundary, and the response was simulated as far as 8 AU. The simulated `output' at 2.2 AU is compared directly with the Pioneer 10 observations at 2.2 AU. Qualitative comparison is good, although several limitations of the one-dimensional theory are noted.