Quasi-stationary planetary waves in late winter Antarctic stratosphere temperature as a possible indicator of spring total ozone

V O Kravchenko,Z I Grytsai,A R Klekociuk,G P Milinevsky,A V Grytsai,O M Evtushevsky

doi:10.5194/acp-12-2865-2012

Abstract

Abstract. Stratospheric preconditions for the annual Antarctic ozone hole are analyzed using the amplitude of quasi-stationary planetary waves in temperature as a predictor of total ozone column behaviour. It is found that the quasi-stationary wave amplitude in August is highly correlated with September–November total ozone over Antarctica with correlation coefficient (r) as high as 0.83 indicating that quasi-stationary wave effects in late winter have a persisting influence on the evolution of the ozone hole during the following three months. Correlation maxima are found in both the lower and middle stratosphere. These likely result from the influence of wave activity on ozone depletion due to chemical processes, and ozone accumulation due to large-scale ozone transport, respectively. Both correlation maxima indicate that spring total ozone tends to increase in the case of amplified activity of quasi-stationary waves in late winter. Since the stationary wave number one dominates the planetary waves that propagate into the Antarctic stratosphere in late austral winter, it is largely responsible for the stationary zonal asymmetry of the ozone hole relative to the South Pole. Processes associated with zonally asymmetric ozone and temperature which possibly contribute to differences in the persistence and location of the correlation maxima are discussed.

Highlights

For over three decades, significant depletion of stratospheric ozone has taken place each austral spring over Antarctica
We present the relationships between the two data sets, the quasi-stationary wave (QSW) amplitude in August inside the polar vortex (70◦ S, 100 hPa (10 hPa)) and the ozone hole area in October during 1985–2010 (Fig. 3a)
The data set size used in this study (26 yr) produces correlation coefficient values |r| ≥ 0.47 that are statistically significant at the 1 % level and less, based on Student’s t-test

Summary

Introduction

Significant depletion of stratospheric ozone has taken place each austral spring over Antarctica. During the 1990s and 2000s, the September mean ozone hole area, measured as the area where the total ozone column (TOC) was less than 220 Dobson Units (DU), was approximately 20–25 million square kilometres (Mkm2) (NOAA, 2009). Over this time period, the September area grew during the 1980s and levelled off in recent years In addition to 2002 and 2004, the ozone holes of 2007 and 2010 were less severe than normal (Tully et al, 2008; WMO, 2010) In this regard, two processes which relate to the timing of the enhanced wave activity are important

Results

Discussion

Conclusion