Structure and long-term change in the zonal asymmetry in Antarctic total ozone during spring

Abstract

Abstract. The quasi-stationary asymmetry of total ozone over Antarctica during spring is studied by TOMS data during the period . Statistics on the amplitude and longitudinal position of zonal anomalies are obtained from the distribution of total ozone along seven individual latitudes at 5-degree intervals between 50 • S and 80 • S. As shown by the September-November means, the mid-latitude collar of ozone-rich stratospheric air has a sub-Antarctic maximum with a mean location in the quadrant 90 • E-180 • E and a total ozone level of about 380 DU between 50 • S and 60 • S. The steady displacement and elongation of the ozone hole under the influence of planetary waves causes a zonal anomaly of low ozone in the sector 0 • -60 • W with total ozone levels of about 200 DU between 70 • S and 80 • S. Climatologically, the highest amplitude of the zonal anomaly is 57.2±13.5 DU (relative asymmetry of 32% between high and low ozone levels) at 65 • S latitude.A significant eastward shift of approximately 45 • in longitude is observed in the total ozone minimum over the Weddell Sea -South Atlantic sector during 1979-2005, whereas the zonal maximum is relatively stable in location. Also apparent is a long-term shift in tropopause temperature distribution in the region.The geographical distribution of the zonal extremes in total ozone for the seven latitudes shows that (i) the extremes exhibit sensitivity to the shape of the Antarctic continent, (ii) the stationarity of the extremes increases poleward above the edge of continent and (iii) the positions of the extremes at the higher latitudes tend to follow the meridionally oriented elements of orography. It is suggested that the radiative influence of Antarctica contributes to the formation of this pattern. Anomalies in the horizontal structure of the tropopause, which appear related to orography, support this view.Correspondence to: G. P. Milinevsky (gmilin@univ.kiev.ua) Mechanisms involved in the formation and decadal change in the total ozone asymmetry, as well as possible influences of the asymmetry on the stratospheric thermal regimes and regional UV irradiance redistribution are discussed.

Zonally asymmetric trends of winter total column ozone in the northern middle latitudes

“…Overall, the wave-3 structure of trends in zonal TCO anomalies shows an eastward shift during the 'ozone recovery' period relative to the period before. A similar eastward shift of zonal TCO anomalies in the Southern Hemisphere during the period 1979-2005 was also reported by Grytsai et al (2007) and they attributed this phenomenon to the decadal changes in planetary waves. The LOTM reproduces the features of trends in zonal TCO anomalies over different regions as exhibited in ERA-Interim data during the two periods (Fig.…”

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

“…It is known that a climatological east-west asymmetry of the Antarctic polar vortex and ozone hole exists with a typical displacement from the South Pole toward the Atlantic sector, 0 • -60 • W (Wirth, 1993;Waugh and Randel, 1999;Grytsai et al, 2007;Agosta and Canziani, 2011). Figure 6 illustrates the changes in the TOC field asymmetry in August under conditions of the strong polar vortex in 2006 (Fig.…”

“…Waugh and Randel, 1999). This, in turn, results in zonal asymmetry of the ozone and temperature fields (Wirth, 1993;Salby and Callaghan, 2004;Grytsai et al, 2007;Canziani et al, 2008). Recent studies show that zonal asymmetry in ozone can influence the planetary wave propagation and zonal mean circulation in the polar stratosphere (Crook et al, 2008;McCormack et al, 2011;Albers and Nathan, 2012).…”

“…It is known that the quasi-stationary planetary wave of zonal wave number 1 (QSW1) dominates the Southern Hemisphere (SH) stratosphere (Randel, 1988;Wirth, 1993;Grytsai et al, 2007;Gabriel et al, 2011) leading to steady displacements of the stratospheric polar vortex relative to the pole (e.g. Waugh and Randel, 1999).…”

Stratospheric ozone change and related climate impacts over 1850–2100 as modelled by the ACCMIP ensemble

“…Stratospheric ozone has been shown to be asymmetrical over the SH polar cap (Grytsai et al, 2007). Prescribing zonal mean ozone fields in CCMs may have implications on SH climate (e.g.…”