Latitude Dependence of the Total Ozone Trends for the Period 2005–2020: TOC for Bulgaria in the Period 1996–2020

The present study examines a long-term statistical trend analysis of Total Ozone Content (TOC) data from the AURA satellite for latitudes 60° and 60° S. A methodology for eliminating the strong dependence on the season has been applied by introducing the relative deviation of the average monthly TOC from the climatological average. The analysis presents comparisons of the trends of the zonal average values of TOC and its relative values. In addition, the standard error of both parameters is calculated. The course of the obtained mass of Ozone (O3) and its trend for the period 2005–2020 is presented, and a division is made into three areas: (i) from 30° S to 30° N, (ii) from 30° S to 60° S, and (iii) from 30° N to 60° N. The last part of this study demonstrates the trends of TOC and relative TOC for Bulgaria in the period 1996–2020. The main results of this study show that (a) in the considered latitude range, a slow but steady increase in O3 prevails, (b) the main part of the O3 mass is in low and mid-latitudes, and (c) the general trend in O3 mass for both hemispheres is determined by the positive trend in the southern hemisphere.