Antarctic ozone loss in 1979–2010: first sign of ozone recovery

J Kuttippurath,J.-P Pommereau,F Lefèvre,H K Roscoe,J D Shanklin,F Goutail,A Pazmiño

doi:10.5194/acp-13-1625-2013

Abstract

Abstract. A long-term ozone loss time series is necessary to understand the evolution of ozone in Antarctica. Therefore, we construct the time series using ground-based, satellite and bias-corrected multi-sensor reanalysis (MSR) data sets for the period 1989–2010. The trends in ozone over 1979–2010 are also estimated to further elucidate its evolution in the wake of decreasing halogen levels in the stratosphere. Our analysis with ground-based observations shows that the average ozone loss in the Antarctic is about −33 to −50% (−90 to −155 DU (Dobson Unit)) in 1989–1992, and then stayed at around −48% (−160 DU). The ozone loss in the warmer winters (e.g. 2002 and 2004) is lower (−37 to −46%), and in the very cold winters (e.g. 2003 and 2006) it is higher (−52 to −55%). These loss estimates are in good agreement with those estimated from satellite observations, where the differences are less than ±3%. The ozone trends based on the equivalent effective Antarctic stratospheric chlorine (EEASC) and piecewise linear trend (PWLT) functions for the vortex averaged ground-based, Total Ozone Mapping Spectrometer/Ozone Monitoring Instrument (TOMS/OMI), and MSR data averaged over September–November exhibit about −4.6 DU yr−1 over 1979–1999, corroborating the role of halogens in the ozone decrease during the period. The ozone trends computed for the 2000–2010 period are about +1 DU yr−1 for EEASC and +2.6 DU yr−1 for the PWLT functions. The larger positive PWLT trends for the 2000–2010 period indicate the influence of dynamics and other basis functions on the increase of ozone. The trends in both periods are significant at 95% confidence intervals for all analyses. Therefore, our study suggests that Antarctic ozone shows a significant positive trend toward its recovery, and hence, leaves a clear signature of the successful implementation of the Montreal Protocol.

Highlights

Servations (e.g. Austin Ient salt.r,u2m01e0;nLtaemtimonen et al, 2006; Tilmes et al, 2006; Hoppel Met ael.t,h2o00d5s), aannddthus this makes the inter-annual comparisoDn avetary Sdiyffisctueltm
No special scaling is performed to account for the differences in the position of the stations in the vortex, as we find the average ozone loss inside the whole vortex
The loss starts in mid-June/early July, in agreement with the appearance of polar stratospheric clouds (PSCs) and heterogeneous chlorine activation on the sunlit parts of the vortex (e.g. Solomon, 1999; Solomon et al, 1986), except during 1989–1990 where it begins in early August

Summary

Introduction

Servations (e.g. Austin Ient salt.r,u2m01e0;nLtaemtimonen et al, 2006; Tilmes et al, 2006; Hoppel Met ael.t,h2o00d5s), aannddthus this makes the inter-annual comparisoDn avetary Sdiyffisctueltm. We present (EEASC) and piecewise linear trend (PWLT) functions for a comprehensive ozone loss analysis in the Antarctic using the vortex averaged ground-based, Total Ozone Mapping Spectrometer/Ozone Monitoring Instrument (TOMS/OMI), ground-based and satellite measurements for the 1989–2010 period, similar to that inHthyedArroctlioc g(Gyouatanildet al., 2005). In and MSR data averaged over September–November exhibit about −4.6 DU yr−1 over 1979–1999, corroborating the role of halogens in the ozone decrease during the period The this we use the same moEdeal, rmtheasSuryemsetentms, and method to construct the whole time series, which makes a continuous, coherent and comparable long-tSercmieannaclyesiss. We consider the measurements inside the vortex and use two additional satellite data sets to check the robustness of the derived trends These data and approach have hitherto not been used for trend studies for this region, which is the significance of this diagnosis.

Methods

Results

Discussion

Conclusion