Abstract
Ground-based and satellite measurements show a 5–7% decrease of total ozone in North America, Europe and Asia in late 1982, resulting in record low (since 1958) total-ozone values in North America and the north temperate zone in early 1983. Total-ozone values appear to be returning to normal later in 1983. Umkehr and ozonesonde-derived estimates of layer-mean ozone in the north temperate zone indicate that this decrease in total ozone was mainly the result of large (10–15%) ozone decreases in the low stratosphere. The ozone deviation in the high stratosphere cannot be properly determined owing to the biasing of upper level Umkehr observations by the optical effects of the stratosphere aerosol from the El Chichón volcanic eruption, but the contribution of these layers to the total ozone, and hence to the total ozone deviation, will be small. Considered briefly is the possible relation between the total-ozone minimum in the winter of 1982–83, the very warm surface temperatures in the north temperate zone in this winter, the pronounced El Niño/Southern Oscillation episode of 1982–83, and the phase of the quasi-biennial oscillation in the tropical stratosphere.
