Impact of ozone layer depletion I: ozone depletion climatology

A monthly ozone profile depletion climatology is constructed for the time period 11/1978–4/1993 for 10° latitude bands using the TOMS total ozone data and SAGE trends. Monthly mean Nimbus-7/TOMS total ozone data are analysed by multiple linear regression which takes into account the seasonal variation, quasi-biennial oscillations (QBO), solar cycle and the month-to-month correlation of ozone values. Total ozone depletion trends and the mean seasonal cycle are determined. To construct the monthly ozone profile depletion climatology the SAGE trends are used down to an altitude of 20 km. The trends between 20 km and the tropopause are estimated from both the TOMS total ozone fields for 1978/79 (the mean seasonal cycle) and 1992/93 (the mean seasonal cycle minus depletion trends) and the SAGE trends; these estimates take into account general information about the seasonal and altitude dependence of trends that is derived from an ozonesonde analysis.