The Trend Profile of Mean Global Total Column Ozone 1964-2009

Abstract

Ground station measurements of total column ozone worldwide in the study period 1964-2009 are aggregated into zonal averages. Latitudinally weighted mean global ozone is estimated from these data on an annual time scale. Trend profile analysis of the mean global ozone time series shows a depletion rate of 0.31 DU per year on average across the entire sample period. The observed ozone depletion rate is not sustained and not of a magnitude that has an implication with respect to the ability of the ozone layer to protect life on the surface of the earth from the harmful effects of UV radiation. The results are consistent with prior results for both ground station and satellite data. The findings are inconsistent with the Montreal Protocol and the Rowland-Molina theory of ozone depletion on which it is based.

Keywords: ozone hole, ozone depletion, Montreal Protocol, halogenated hydrocarbons, ozone layer