Analysis of October SBUV ozone profile data in the antarctic polar vortex shows that there was a decrease in ozone between 1979 and 1984 of between 15 and 30% at all levels from 30 mb to 0.7 mb. During spring of 1983 at 75¿ to 80 ¿S the ozone mixing ratio at 1 mb decreases continuously from September through the summer solstice and then increases in late summer and fall, but we observe much less ozone at 1 mb in September and October than under similar conditions in the fall. This asymmetry between spring and fall ozone values may be the direct result of the sudden release of chlorine bound by meteoric material during polar night. Meteoric atoms, X, descending from the mesosphere react with the atmosphere to produce XOH, which will interact with HCl to form salts, XCl. Since these processes continue in the absence of sunlight chlorine may accumulate during polar winter. The sudden release of this chlorine from photodissociation of these salts during spring could give rise to the loss of ozone in the upper stratosphere. At 30 mb ozone decreases substantially in mid-September and remains at a low value until the mid-October increase. Different mechanisms may be required to explain the ozone decreases in the upper stratosphere and in the lower stratosphere. |