Field Research on Changes in Polar Atmospheric Environment -Polar Ozone Depletion-

点击翻译按钮获取中文摘要

Stratospheric ozone depletion is tought to be due to increase in CFCs content and decrease in stratospheric temperature caused by green house effect gases, and polar stratospheric clouds seem to play an important role in the ozone loss. Denitrification of the stratosphere through appearance of polar strotospheric clouds (PSCs) is suggested an essential process controlling CLOx catalytic ozone depletion reactions. However, detailed processes are still uncertain.In this research balloon measurement on NOx, ozone, and aerosols was made at Sweden, Kiruna in witer of 1990/1991 and 1991/1992, and Lidar measurements on stratospheric aerosols in winter of 1991 at Alacka, Fairbanks.From the balloon measurements, ozone depletion. Low content of NOx, and increase in aerosol content were identified in the lower stratosphere. Considering that the atmospheric temperature of this region decreased to the frost point temperature of nitric acid trihydrates, it is suggested that from of type-1 PSCs, NAT couses lage denitrification and consequentory ozone decreases through activation of ozone loss reaction of CLOx. However, quantitative relations between those are still unclear. In winter of 1991/1992, NOx depletion was measured but meaningful ozone depletion was not identified.The lidar measurements showed that volcanic disturbance of Mt. Pinatubo had diffused to high Latitudes by mid-December of 1991. Such large scale disturbance of volcanisum may activate denitrification of stratosphere which can trigar ozone loss. It is necessary to understand global dispresion of the volcanic cloud to assess stratospheric ozone change.