Stratospheric ozone chemistry in the Antarctic: what determines the lowest ozone values reached and their recovery? - Archive ouverte HAL Access content directly
Journal Articles Atmospheric Chemistry and Physics Year : 2011

Stratospheric ozone chemistry in the Antarctic: what determines the lowest ozone values reached and their recovery?

, , (1, 2) , ,
1
2
J. -U. Grooss
  • Function : Author
K. Brautzsch
  • Function : Author
S. Solomon
  • Function : Author
R. Müller
  • Function : Author

Abstract

Balloon-borne observations of ozone from the South Pole Station have been reported to reach ozone mixing ratios below the detection limit of about 10 ppbv at the 70 hPa level by late September. After reaching a minimum, ozone mixing ratios increase to above 1 ppmv on the 70 hPa level by late December. While the basic mechanisms causing the ozone hole have been known for more than 20 yr, the detailed chemical processes determining how low the local concentration can fall, and how it recovers from the minimum have not been explored so far. Both of these aspects are investigated here by analysing results from the Chemical Lagrangian Model of the Stratosphere (CLaMS). As ozone falls below about 0.5 ppmv, a balance is maintained by gas phase production of both HCl and HOCl followed by heterogeneous reaction between these two compounds in these simulations. Thereafter, a very rapid, irreversible chlorine deactivation into HCl can occur, either when ozone drops to values low enough for gas phase HCl production to exceed chlorine activation processes or when temperatures increase above the polar stratospheric cloud (PSC) threshold. As a consequence, the timing and mixing ratio of the minimum ozone depends sensitively on model parameters, including the ozone initialisation. The subsequent ozone increase between October and December is linked mainly to photochemical ozone production, caused by oxygen photolysis and by the oxidation of carbon monoxide and methane.
Fichier principal
Vignette du fichier
acp-11-12217-2011.pdf (1.13 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03622590 , version 1 (29-03-2022)

Licence

Attribution - CC BY 4.0

Identifiers

Cite

J. -U. Grooss, K. Brautzsch, R. Pommrich, S. Solomon, R. Müller. Stratospheric ozone chemistry in the Antarctic: what determines the lowest ozone values reached and their recovery?. Atmospheric Chemistry and Physics, 2011, 11, pp.12217-12226. ⟨10.5194/acp-11-12217-2011⟩. ⟨insu-03622590⟩
22 View
4 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More