Intra‐annual relationships between polar ozone and the SAM

Fogt, Ryan L.; Perlwitz, Judith; Pawson, Steven; Olsen, Mark A.

doi:10.1029/2008gl036627

Cited by 25 publications

(38 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The strengthening SAM in the RCP8.5, in turn, may even itself modulate the ozone concentration. Positive phases of the SAM are often linked with decreasing ozone over the following several months (Fogt et al 2009b). Therefore, the increasing trend in the SAMI caused by GHGs may reduce the ozone concentration and is likely to reduce the impact of decreasing ozone-depleting substances on ozone recovery, which may impede the recovery.…”

Section: Discussionmentioning

confidence: 97%

“…The project follows on from the previous CMIP3. However, whereas in CMIP3 ozone concentrations were usually fixed, in the CMIP5 models ozone is time dependent, an essential factor in accurately handling the temporal evolution of ozone destruction and recovery according to findings by Cai and Cowan (2007) and Fogt et al (2009a).…”

Section: A Modelsmentioning

confidence: 98%

“…In fact, simulations and projections of the SAM have been investigated in several studies using phase 3 of CMIP (CMIP3); for example, Cai and Cowan (2007) and Fogt et al (2009a) found that most CMIP3 models captured the recent positive SAM trends in the austral summer, but models containing time-variable ozone produced larger significant trends. Simpkins and Karpechko (2012) However, most studies evaluating model performance in describing the present-day SAM have focused mainly on the linear trend component.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Simulation and Projection of the Southern Hemisphere Annular Mode in CMIP5 Models

et al. 2013

View full text Add to dashboard Cite

Climate variability in the Southern Hemisphere (SH) extratropical regions is dominated by the SH annular mode (SAM). Future changes in the SAM could have a large influence on the climate over broad regions. In this paper, the authors utilized model simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5) to examine projected future changes in the SAM during the austral summer [December-February (DJF)]. To start off, first, the ability of the models in reproducing the recently observed spatial and temporal variability was assessed. The 12 CMIP5 models examined were found to reproduce the SAM's spatial pattern reasonably well in terms of both the symmetrical and the asymmetric component. The CMIP5 models show an improvement over phase 3 of CMIP (CMIP3) in simulating the seesaw structure of the SAM and also give improvements in the recently observed positive SAM trend. However, only half the models appeared to be able to capture two major recent decadal SAM phases. Then, the future SAM trends and its sensitivity to greenhouse gas (GHG) concentrations using simulations based on the representative concentration pathways 4.5 (RCP4.5) and 8.5 (RCP8.5) were explored. With RCP4.5, a very weak negative trend for this century is found. Conversely, with RCP8.5, a significant positive trend was projected, with a magnitude similar to the recently observed trend. Finally, model uncertainty in the future SAM projections was quantified by comparing projections from the individual CMIP5 models. The results imply the response of SH polar region stratospheric temperature to GHGs could be a significant controlling factor on the future evolution of the SAM.

show abstract

Section: Discussionmentioning

confidence: 97%

Section: A Modelsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Simulation and Projection of the Southern Hemisphere Annular Mode in CMIP5 Models

et al. 2013

View full text Add to dashboard Cite

show abstract

“…A correlation between Antarctic stratospheric ozone depletion and the SAM index has been seen in observations Arblaster and Meehl, 2006;Wang et al, 2011; and references therein) and models (Perlwitz et al, 2008;Son et al, 2008;Thompson et al, 2011). The largest variability in the Antarctic stratosphere associated with the SAM signal is observed in the September-December period (Fogt et al, 2009). …”

Section: Proxy Data Setsmentioning

confidence: 99%

Long-term changes in the upper stratospheric ozone at Syowa, Antarctica

et al. 2014

View full text Add to dashboard Cite

Abstract. Analyses of stratospheric ozone data determined from Dobson-Umkehr measurements since 1977 at the Syowa (69.0 • S, 39.6 • E), Antarctica, station show a significant decrease in ozone at altitudes higher than that of the 4 hPa pressure level during the 1980s and 1990s. Ozone values over Syowa have remained low since 2001. The time series of upper stratospheric ozone from the homogenized NOAA SBUV (Solar Backscatter Ultraviolet Instrument)(/2) 8.6 overpass data (±4 • , 24 h) are in qualitative agreement with those from the Syowa station data. Ozone recovery during the austral spring over the Syowa station appears to be slower than predicted by the equivalent effective stratospheric chlorine (EESC) curve. The long-term changes in the station's equivalent latitude (indicative of vortex size/position in winter and spring) are derived from MERRA (Modern Era Retrospective-analysis for Research and Applications) reanalyses at ∼ 2 and ∼ 50 hPa. These data are used to attribute some of the upper and middle stratospheric ozone changes to the changes in vortex position relative to the station's location. In addition, high correlation of the Southern Hemisphere annular mode (SAM) with polar upper stratospheric ozone during years of maximum solar activity points toward a strong relationship between the strength of the Brewer-Dobson circulation and the polar stratospheric ozone recovery. In the lower stratosphere, ozone recovery attributable to CFCs (chlorofluorocarbons) is still not definitive, whereas the recovery of the upper stratosphere is slower than predicted. Further research indicates that dynamical and other chemical changes in the atmosphere are delaying detection of recovery over this station.

show abstract

“…It can be observed that in the last years of when the polar vortex was stronger, the final breakdown takes place later than for years with a weaker one. Some studies have been done to analyse the potential factors contributing to the evolution of the Antarctic polar vortex and were in particular focused on the delay in its breakdown (Haigh and Roscoe, 2009;Fogt et al, 2009;Perlwitz et al, 2008;Gillett and Thompson, 2003). Their results have demonstrated that ozone depletion is a major factor influencing the delay in the polar vortex breakup, while the combined effects of solar activity, the phase of the quasi-biennial oscillation and greenhouse gases exert only a small influence.…”

Section: Ozone Variability In November and Decembermentioning

confidence: 99%

Antarctic ozone variability inside the polar vortex estimated from balloon measurements

et al. 2014

View full text Add to dashboard Cite

Abstract. Thirteen years of ozone soundings at the Antarctic Belgrano II station (78 • S, 34.6 • W) have been analysed to establish a climatology of stratospheric ozone and temperature over the area. The station is inside the polar vortex during the period of development of chemical ozone depletion. Weekly periodic profiles provide a suitable database for seasonal characterization of the evolution of stratospheric ozone, especially valuable during wintertime, when satellites and ground-based instruments based on solar radiation are not available. The work is focused on ozone loss rate variability (August-October) and its recovery (NovemberDecember) at different layers identified according to the severity of ozone loss. The time window selected for the calculations covers the phase of a quasi-linear ozone reduction, around day 220 (mid-August) to day 273 (end of September). Decrease of the total ozone column over Belgrano during spring is highly dependent on the meteorological conditions. Largest depletions (up to 59 %) are reached in coldest years, while warm winters exhibit significantly lower ozone loss (20 %). It has been found that about 11 % of the total O 3 loss, in the layer where maximum depletion occurs, takes place before sunlight has arrived, as a result of transport to Belgrano of air from a somewhat lower latitude, near the edge of the polar vortex, providing evidence of mixing inside the vortex. Spatial homogeneity of the vortex has been examined by comparing Belgrano results with those previously obtained for South Pole station (SPS) for the same altitude range and for 9 yr of overlapping data. Results show more than 25 % higher ozone loss rate at SPS than at Belgrano. The behaviour can be explained taking into account (i) the transport to both stations of air from a somewhat lower latitude, near the edge of the polar vortex, where sunlight reappears sooner, resulting in earlier depletion of ozone, and (ii) the accumulated hours of sunlight, which become much greater at the South Pole after the spring equinox. According to the variability of the ozone hole recovery, a clear connection between the timing of the breakup of the vortex and the monthly ozone content was found. Minimum ozone concentration of 57 DU in the 12-24 km layer remained in November, when the vortex is more persistent, while in years when the final stratospheric warming took place "very early", mean integrated ozone rose by up to 160-180 DU.

show abstract

Intra‐annual relationships between polar ozone and the SAM

Cited by 25 publications

References 15 publications

Simulation and Projection of the Southern Hemisphere Annular Mode in CMIP5 Models

Simulation and Projection of the Southern Hemisphere Annular Mode in CMIP5 Models

Long-term changes in the upper stratospheric ozone at Syowa, Antarctica

Antarctic ozone variability inside the polar vortex estimated from balloon measurements

Contact Info

Product

Resources

About