The spatial extent and the ionization profiles within the extended oval-shaped regions irradiated by the intense solar particle events (SPE) of August 1972 have been derived from high-energy proton data obtained with the 1971-089A polar-orbiting satellite and from several balloon flights. The particle ionization during the most intense 10-hour period of the event on August 4 greatly enhanced the concentrations of short-lived HOx and long-lived NOx constituents, which in turn were responsible for the creation of a polar ozone cavity (POC) that has been identified and tracked with the backscattered ultraviolet (BUV) ozone sensors on the Nimbus 4 satellite. At the end of the peak irradiation period the ozone concentrations within the northern hemisphere POC were reduced by 46, 16, and 4% of altitudes of 49.5, 41, and 32 km, respectively. The total columnar ozone is estimated to have been reduced by ~2% at this time. Above ~45 km the ozone recovered on the time scale of several days. At 38.7 km in the northern hemisphere, however, the POC persisted and rotated as a semirigid mass in an east-to-west direction for some 53 days until the autumnal changes in wind patterns finally prevented further tracking. Time-dependent chemistry calculations have been performed to explain the cause, magnitude, and temporal features of the ozone reductions. Using the calculated diurnal and particle-induced behavior of the ozone during the SPE, the changes in heating rate and temperature expected in the stratosphere have been estimated. As a result of the initial large HOx-caused ozone reduction, the temperature at 45 km should have decreased by ~4¿K several days after the event. Attempts to verify the predicted temperature changes have been unsuccessful due to limitations in the temperature measurement techniques.