TITLE:
Status of Stratospheric Ozone over Pakistan 1987-2008
AUTHORS:
Maida Zahid, Ghulam Rasul
KEYWORDS:
Ozone Layer Depletion, Stratosphere, Greenhouse Gases GHG’s and Solar Radiation
JOURNAL NAME:
Journal of Environmental Protection,
Vol.1 No.4,
December
28,
2010
ABSTRACT: The ozone layer depletion and its harmful impact on living beings have been a greater concern of all the scientists all over the world. The aim of this paper is to reveal the current status of stratospheric ozone over Pakistan. The annual, monthly and seasonal analyses have been performed in order to check the status. The variation in total column of ozone has been observed during these analyses and decrease in total column of ozone has been seen in all the investigations from 1987-2008. The correlation coefficient for JRA forecasted data and observed ozone data is 0.6. Both the data sets show decline in ozone concentration. The total change calculated in annual depth of ozone is ?5.67 D.U and ?4.2 D.U in monthly depth of ozone. The seasonal analysis shows that the total change in ozone in summer is ?6.3 D.U, in spring ?10.5 D.U, in winter ?3.15 D.U and in autumn ?2.0 D.U. Maximum change in ozone thickness has been found in spring and minimum in autumn. The solar radiations, decrease in temperatures of stratosphere and carbon dioxide (CO2) play significant role in ozone layer depletion. According to the findings of this study solar radiations and carbon dioxide (CO2) are inversely proportional to the total column of ozone. The correlation coefficient for solar radiations and ozone on annual basis is 0.44 (R2 = 0.44) and on monthly basis is around 0.35 (R2 = 0.35). Therefore the more intense the solar radiations the more ozone layer thinning will occur. The correlation coefficient for ozone and carbon dioxide is around 0.3 (R2 = 0.3) during the study period. The decrease in stratospheric temperatures will cause the cooling of stratosphere which is ultimately responsible for ozone layer depletion. The total decrease analyzed in stratospheric temperatures during the study period is about ?1.3℃. It is observed that alarming rise in carbon dioxide (CO2) concentration is not only contributing to global warming in troposphere but cooling in the stratosphere.