Total ozone mass calculation to assess the global ozone behavior

Abstract

This work presents an assessment of the global and hemispheric total ozone mass and its interannual variations, using the total number of daily satellite measurements from the Total Ozone Mapping Spectrometer (TOMS) version 8 and Ozone Monitoring Instrument (OMI) level 3. The mean total ozone mass was 3.1283 ± 0.1337 × 10 12 kg from November 1978 to November 1979, and 2.9979 ± 0.0917 × 10 12 kg from November 2004 to November 2005. The difference (1.3033 ± 0.3221 × 10 11 kg) represents a 4.2 ± 0.3% decrease in 26 yrs (1.615 ± 0.113% per decade), around 3% corresponding to the Northern Hemisphere and 5% corresponding to the Southern Hemisphere; 1.2 and 2.0% per decade, respectively. Differences in total ozone mass trends between Northern and Southern hemispheres indicate a change in geographic ozone distribution in the Southern Hemisphere. A linear fit between November 1978 and November 1991 shows a global ozone decrease of 4.72 × 10 9 kg per year, representing a loss of 1.5% per decade. Additionally, we found a net interannual variation of 16% of the total quantity existing during the equinoxes, when the maximum annual total ozone mass is reached.