Stratospheric clouds and ozone depletion in the Arctic during January 1989

Abstract

Stratospheric clouds, believed to be necessary for springtime polar ozone depletion to take place, were detected with balloon-borne sensors at Kiruna, Sweden during January 1989, the coldest January in the north polar stratosphere for at least 25 years. Comparison of the ozone profile in the region of the clouds with those obtained during the past three austral spring seasons at McMurdo Station in Antarctica suggests the beginning of ozone depletion at a height of 22–26 km.