Περίληψη:
Among the most important aspects of the atmospheric pollution problem are the anthropogenic impacts on the stratospheric ozone layer, the related trends of the total ozone content drop and the solar ultraviolet radiation enhancement at the Earth's surface level, which originate various dangers for man and ecosystems. The present study is devoted to the total ozone depletion over Antarctica and the mid-latitude zone of the northern hemisphere, by using the remote sensing techniques. The ozone hole over Antarctica in late September 2002 was gradually elongated, and reached finally to the splitting into two holes, probably due to a polar stratospheric major warming, which was presumably taking place. At Athens, the difference in wintertime tropopause height distribution for the pre- and post-Pinatubo period appears a main maximum around 11.3 km, with a secondary one around 9.3 km. This difference in summertime distribution appears one main maximum around 11.3 km and a secondary one around 17.3 km. In addition, any column ozone decrease is always accompanied by an increase in tropopause height, with a rate of -9.4 DU/km in summer, -14.7 DU/km, in winter, during the pre-Pinatubo period and -7.5 DU/km in summer, and -9.3 DU/km, in winter, during the post-Pinatubo period. Also, the linear regression analysis of the deseasonalized monthly mean column ozone indicates a long-term decrease of -2.2 and -3.7 DU per decade, for the pre- and post-Pinatubo period, respectively. Furthermore, the long-term increase of tropopause height at Athens is about 377 and 207 m per decade for the pre- and post-Pinatubo period, respectively. The above-mentioned results suggest that a close connection between the increase of tropopause height, tropospheric warming, and TOC depletion, might exists, depending on the events of volcanic eruptions. © 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.
Λέξεις-κλειδιά:
Air pollution; Ecosystems; Global warming; Ozone layer; Troposphere; Ultraviolet radiation; Upper atmosphere; Volcanoes, Hemisphere; Ozone hole; Polar warming, Space research, anthropogenic effect; atmospheric pollution; ozone depletion; remote sensing; stratosphere; tropopause; ultraviolet radiation
