Relationship of springtime ozone depletion at arrival heights, Antarctica, to the 70 HPa temperatures

The total ozone measurements from Arrival Heights (78°S) show severe depletion occurring in 1989 and 1990 with the minimum ozone values of 164 and 144 Dobson Units (DU) being measured in early October. These depletions represent the loss of about half of the total ozone column. Much milder ozone depletion was observed in the 1988 spring, with the minimum of 217 DU being observed on 23 September. The ozone depletion mechanism is linked to the occurrence of polar stratospheric clouds, and hence with low temperatures in the lower stratosphere in early spring. The Arrival Heights data show a shift in the ozone‐temperature relationship over the last three years, with the same total ozone values associated with progressively higher temperatures from year to year.