Age of stratospheric air unchanged within uncertainties over the past 30 years

Abstract

The rising abundances of greenhouse gases in the atmosphere is associated with an increase in radiative forcing that leads to warming of the troposphere, the lower portion of the Earth’s atmosphere, and cooling of the stratosphere above1. A secondary effect of increasing levels of greenhouse gases is a possible change in the stratospheric circulation2,3, which could significantly affect chlorofluorocarbon lifetimes4, ozone levels5,6 and the climate system more generally7. Model simulations have shown that the mean age of stratospheric air8 is a good indicator of the strength of the residual circulation9, and that this mean age is expected to decrease with rising levels of greenhouse gases in the atmosphere10. Here we use balloon-borne measurements of stratospheric trace gases over the past 30 years to derive the mean age of air from sulphur hexafluoride (SF6) and CO2 mixing ratios. In contrast to the models, these observations do not show a decrease in mean age with time. If models are to make valid predictions of future stratospheric ozone levels, and of the coupling between ozone and climate change, a correct description of stratospheric transport and possible changes in the transport pathways are necessary.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Vertical profiles of CO2 in the mid-latitude stratosphere.
Figure 2: Vertical profiles of mean age derived from the CO2 data shown in Fig. 3.
Figure 3: Long-term evolution of mean age above 24 km altitude.

References

  1. 1

    Solomon, S. et al. (eds) Climate Change 2007: The Physical Science Basis—Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge Univ. Press, 2007).

  2. 2

    Butchart, N. et al. Simulations of anthropogenic change in the strength of the Brewer–Dobson circulation. Clim. Dyn. 27, 727–741 (2006).

  3. 3

    McLandress, C. & Shepherd, T. G. Simulated anthropogenic changes in the Brewer–Dobson circulation, including its extension to high latitudes. J. Clim. 10.1175/2008JCLI2679.1 (2008, in the press).

  4. 4

    Butchart, N. & Scaife, A. A. Removal of chlorofluorocarbons by increased mass exchange between the stratosphere and troposphere in a changing climate. Nature 410, 799–802 (2001).

  5. 5

    Shepherd, T. G. Dynamics, stratospheric ozone, and climate change. Atmos. Oceanogr. 46, 371–392 (2008).

  6. 6

    Eyring, V. et al. Multimodel projections of stratospheric ozone in the 21st century. J. Geophys. Res. 112, D16303 (2007).

  7. 7

    Baldwin, M. P., Dameris, M. & Shepherd, T. G. How will the Stratosphere affect climate change? Science 316, 5831 (2007).

  8. 8

    Waugh, D. W. & Hall, T. M. Age of stratospheric air: Theory, observations and models. Rev. Geopyhs. 40, 1–10 (2002).

  9. 9

    Li, S. & Waugh, D. W. Sensitivity of mean age and long-lived tracers to transport parameters in a two-dimensional model. J. Geophys. Res. 104, 30559–30569 (1999).

  10. 10

    Austin, J. & Li, F. On the relationship between the strength of the Brewer–Dobson circulation and the age of stratospheric air. Geophys. Res. Lett. 33, L17807 (2006).

  11. 11

    Thompson, D. W. J. & Solomon, S. Recent stratospheric climate trends as evidenced in radiosonde data: Global structure and tropospheric linkages. J. Clim. 18, 4785–4795 (2005).

  12. 12

    Schmidt, U. & Khedim, A. In situ measurements of carbon dioxide in the winter Arctic vortex and at mid latitudes: An indicator of the ‘age’ of stratospheric air. Geophys. Res. Lett. 18, 763–766 (1991).

  13. 13

    Harnisch, J., Borchers, R., Fabian, P. & Maiss, M. Tropospheric trends for CF4 and C2F6 since 1982 derived from SF6 dated stratospheric air. Geophys. Res. Lett. 23, 1099–1102 (1996).

  14. 14

    Engel, A. et al. The temporal development of total chlorine in the high latitude stratosphere based on reference distributions of mean age derived from CO2 and SF6 . J. Geophys. Res. 107, 10.1029/2001JD000584 (2002).

  15. 15

    Andrews, A. E. et al. Mean ages of stratospheric air derived from in situ observations of CO2, CH4, and N2O. J. Geophys.Res. 106, 32295–32314 (2001).

  16. 16

    Boering, K. A. et al. Stratospheric mean ages and transport rates from observations of carbon dioxide and nitrous oxide. Science 274, 1340–1343 (1996).

  17. 17

    Nakazawa, T. et al. Measurements of the stratospheric carbon dioxide concentration over Japan using a balloon-borne cryogenic sampler. Geophys. Res. Lett. 22, 1229–1232 (1995).

  18. 18

    Moore, F. L. et al. Balloonborne in situ gas chromatograph for measurements in the troposphere and stratosphere. J. Geophys. Res. 108, 10.1029/2002GL016240 (2003).

  19. 19

    Lueb, R. A., Ehhalt, D. H. & Heidt, L. E. Balloon-borne low temperature air sampler. Rev. Sci. Instrum. 46, 702–705 (1975).

  20. 20

    Engel, A. et al. Observation of mesospheric air inside the arctic stratospheric polar vortex in early 2003. Atmos. Chem. Phys. 6, 267–282 (2006).

  21. 21

    Ma, J. et al. Interannual variability of stratospheric trace gases: The role of extratropical wave driving. Q. J. R. Meteorol. Soc. 130, 2459–2474 (2004).

  22. 22

    Austin, J., Wilson, J., Li, F. & Voemel, H. Evolution of water vapor and age of air in coupled chemistry climate model simulations of the stratosphere. J. Atmos. Sci. 64, 905–921 (2007).

  23. 23

    Garcia, R. R. et al. Simulation of secular trends in the middle atmosphere, 1950–2003. J. Geophys. Res. 112, D09301 (2007).

  24. 24

    Garcia, R. R. & Randel, W. J. Acceleration of the Brewer–Dobson circulation due to increases in greenhouse gases. J. Atmos. Sci. 65, 2731–2739 (2008).

  25. 25

    Rosenlof, K. H. et al. Hemispheric asymmetries in water vapor and inferences about transport in the lower stratosphere. J. Geophys. Res. 102, 13213–13234 (1997).

  26. 26

    Plumb, R. A. ‘Tropical pipe’ model of stratospheric transport. J. Geophys. Res. 101, 3957–3972 (1996).

  27. 27

    Grant, W. B. et al. Use of volcanic aerosols to study the tropical stratospheric reservoir. J. Geophys. Res. 101, 3973–3988 (1996).

  28. 28

    Hall, T. H. & Plumb, R. A. Age as a diagnostic of stratospheric transport. J. Geophys. Res. 99, 1059–1070 (1994).

  29. 29

    Rosenlof, K. H. & Holton, J. R. Estimates of the stratospheric residual circulation using the downward control principle. J. Geophys. Res. 98, 10465–10479 (1993).

Download references

Acknowledgements

The authors would like to acknowledge financial support from various national and international funding agencies over the past 30 years. University of Frankfurt would in particular like to acknowledge financial support from DFG under the CAWSES priority programme and to CNES for successful balloon operations. The authors also express their gratitude to the Scientific Balloon Center of the Institute of Space and Astronautical Science, JAXA for their cooperation in stratospheric air sampling, and the NASA Upper Atmosphere Research Program for financial support and the US National Scientific Balloon Facility for launch support. This work was partially supported by the Grants-in-Aid for Creative Scientific Research (2005/17GS0203) of the Ministry of Education, Science, Sports and Culture, Japan. We further acknowledge the pioneering work by R. Lueb, D. H. Ehhalt, W. Pollock and L. Heidt (NCAR) in developing and deploying a cryogenic whole air sampler for balloon-borne atmospheric science, and B. Daube for the development and deployment of the in situ CO2 airborne analyser.

Author information

Correspondence to A. Engel or F. Moore or D. Hurst.

Supplementary information

Supplementary Information

Supplementary Information (PDF 173 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Engel, A., Möbius, T., Bönisch, H. et al. Age of stratospheric air unchanged within uncertainties over the past 30 years. Nature Geosci 2, 28–31 (2009) doi:10.1038/ngeo388

Download citation

Further reading