Model Analysis of Stratosphere-Troposphere Exchange of Ozone and Its Role in the Tropospheric Ozone Budget
Anthropogenic activities have changed the chemical composition of the atmosphere. It is generally accepted that tropospheric ozone (O3) has increased considerably during industrialization as a result of the photochemical transformation of anthropogenically emitted ozone precursors such as nitrogen oxides (NOx), methane (CH4), carbon monoxide (CO), and nonmethane hydrocarbons (NMHC) . Analysis of measurement data from the second half of the last century reveals that typical ozone mixing ratios in Europe at the surface were between 10 and 15 parts per billion by volume (ppbv) [2,3]. At present, surface ozone mixing ratios over Europe are, on average, between 20 and 50 ppbv . This indicates that anthropogenic activities have caused a boundary layer ozone increase of more than a factor of two, at least in Europe. Additionally, diffusive and convective transports cause exchange of air between the boundary layer and the free troposphere, carrying ozone and ozone precursors to higher altitudes. Comparison between historical and contemporary measurements carried out over the Alps (representative of continental background conditions), shows an ozone increase of about 20 ppbv at least up to about 4 km altitude . Model calculations indicate that the tropospheric content of ozone has increased from about 190 Tg (1 Tg = 1012 g) in the preindustrial era to 270 Tg at present .
KeywordsOzone Concentration Potential Vorticity Stratospheric Ozone Tropospheric Ozone Lower Stratosphere
Unable to display preview. Download preview PDF.
- 1.World Meteorological Organization (1992) Scientific assessment of ozone depletion: 1991, Global ozone research and monitoring project. Rep. 25, Geneva, Switzerland.Google Scholar
- 10.Holton, J.R. and Lelieveld, J. (1996) Stratosphere-troposphere exchange and its role in the budget of tropospheric ozone, in P.J. Crutzen and V. Ramanathan (Eds.) Clouds,Chemisty and Climate NATO ASI Series, Springer-Verlag, Berlin, pp. 173–190.Google Scholar
- 18.Roelofs, G.J., and Lelieveld, J. (1997) Model study of the influence of cross-tropopause O3 transports on tropospheric O3 levelsTellus 49B.3855.Google Scholar
- 19.Ertel, H. (1942) Ein neuer hydrodynamischer WirbelsatzMeteorol. Z 59, 277–281.Google Scholar
- 26.Roeckner, E., Arpe, K., Bengtsson, L., Christoph, M., Claussen, M., Dörrenil, L., Esch, M., Giorgetta, M., Schlese, U., and Schuizweida U. (1996) The atmospheric general circulation model ECHAM-4: Model description and simulation of present-day climate, Rep. 218, Max-PlanckInstitute for Meteorology, Hamburg, Germany.Google Scholar
- 32.Roelofs, G.J. (1999) Dynamic parameterization of stratospheric ozone in the chemistry-ECHAM using MOZAIC data, in A. Marenco (Coord.), Minutes of the MOZAIC-11 meeting held in FZ/Juelich on 27–29 January 1999, Université Paul Sabatier, Toulouse, pp. 172–176.Google Scholar
- 33.Kentarchos, A.S., Roelofs, G.J., and Lelieveld, J. (1999) Simulation of extratropical synoptic scale stratosphere-troposphere exchange using a coupled chemistry-GCM: Sensitivity to horizontal resolution, submitted to J. Atm. Sci Google Scholar
- 34.DeMore, W.B., et al. (1997) Chemical kinetics and photochemical data for use in stratospheric modeling, Evaluation number 12, JPL Publ. 97–4 Google Scholar
- 39.Crutzen, P.J., and Zimmermann, P.H. (1991) The changing photochemistry of the troposphere, Tellus 43AB.136–151.Google Scholar
- 41.Intergovernmental Panel on Climate Change (IPCC) (1992) Climate Change, J.T. Houghton, B.A. Callander, and S.K. Varney (Eds.), Cambridge University Press, New York.Google Scholar