Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Warming maximum in the tropical upper troposphere deduced from thermal winds


Climate models and theoretical expectations have predicted that the upper troposphere should be warming faster than the surface. Surprisingly, direct temperature observations from radiosonde and satellite data have often not shown this expected trend. However, non-climatic biases have been found in such measurements. Here we apply the thermal-wind equation to wind measurements from radiosonde data, which seem to be more stable than the temperature data. We derive estimates of temperature trends for the upper troposphere to the lower stratosphere since 1970. Over the period of observations, we find a maximum warming trend of 0.65±0.47 K per decade near the 200 hPa pressure level, below the tropical tropopause. Warming patterns are consistent with model predictions except for small discrepancies close to the tropopause. Our findings are inconsistent with the trends derived from radiosonde temperature datasets and from NCEP reanalyses of temperature and wind fields. The agreement with models increases confidence in current model-based predictions of future climate change.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Radiosonde wind trends for 1979–2005.
Figure 2: Trend in wind-estimated meridional temperature gradient versus the corresponding trend from temperature data for 1979–2005.
Figure 3: Meridional sections of atmospheric temperature trends.


  1. Karl, T. R., Hassol, S. J., Miller, C. D. & Murray, W. L. (eds) Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences (A report by the Climate Change Science Program and the Subcommittee on Global Change Research, Washington, 2006).

  2. Lanzante, J. R., Klein, S. A. & Seidel, D. J. Temporal homogenization of radiosonde temperature data. Part II: Trends, sensitivities, and MSU comparison. J. Clim. 16, 241–262 (2003).

    Article  Google Scholar 

  3. Free, M. et al. Radiosonde atmospheric temperature products for assessing climate (RATPAC): A new data set of large-area anomaly time series. J. Geophys. Res. 110, doi:10.1029/2005JD006169 (2005).

  4. Thorne, P. W. et al. Revisiting radiosonde upper air temperatures from 1958 to 2002. J. Geophys. Res. 110, doi:10.1029/2004JD005753 (2005).

  5. Sherwood, S. C., Meyer, C. L., Allen, R. J. & Titchner, H. A. Robust tropospheric warming revealed by iteratively homogenized radiosonde data. J. Clim.doi:10.1175/2008JCLI2320.1 (2008, in the press).

  6. Haimberger, L. Homogenization of radiosonde temperature time series using innovation statistics. J. Clim. 20, 1377–1403 (2007).

    Article  Google Scholar 

  7. Santer, B. D. et al. Amplification of surface temperature trends and variability in the tropical atmosphere. Science 309, 1551–1556 (2005).

    Article  Google Scholar 

  8. Douglass, D. H., Christy, J. R., Pearson, B. D. & Singer, S. F. A comparison of tropical temperature trends with model predictions. Int. J. Climatol, Published online in Wiley InterScience doi:10.1002/joc.1651 (2007).

  9. Sherwood, S. C., Lanzante, J. R. & Meyer, C. L. Radiosonde daytime biases and late 20th century warming. Science 309, 1556–1559 (2005).

    Article  Google Scholar 

  10. Randel, W. J. & Wu, F. Biases in stratospheric and tropospheric temperature trends derived from historical radiosonde data. J. Clim. 19, 2094–2104 (2006).

    Article  Google Scholar 

  11. Free, M. & Seidel, D. J. Comments on biases in stratospheric and tropospheric temperature trends derived from historical radiosonde data’. J. Clim. 20, 3704–3709 (2007).

    Article  Google Scholar 

  12. Christy, J. R., Norris, W. B., Spencer, R. W. & Hnilo, J. J. Tropospheric temperature change since 1979 from tropical radiosonde and satellite measurements. J. Geophys. Res. 112, doi:10.1029/2005JD006881 (2007).

  13. Haimberger, L., Tavolato, C. & Sperka, S. Towards elimination of the warm bias in historic radiosonde temperature records—some new results from a comprehensive intercomparison of upper air data. Meteorol. Z 17 (2008, in the press).

  14. Fu, Q., Johanson, C. M., Warren, S. G. & Seidel, D. J. Contribution of stratospheric cooling to satellite inferred tropospheric temperature trends. Nature 429, 55–58 (2004).

    Article  Google Scholar 

  15. Fu, Q. & Johanson, C. M. Satellite-derived vertical temperature dependence of tropical tropospheric trends. Geophys. Res. Lett. 32, doi:10.1029/2004GL022266 (2005).

  16. Mears, C. A. & Wentz, F. W. The effect of diurnal correction on satellite derived lower tropospheric temperature. Science 309, 1548–1551 (2005).

    Article  Google Scholar 

  17. McCarthy, M. P. et al. Assessing bias and uncertainty in the HadAT adjusted radiosonde climate record. J. Clim. 21, 817–832 (2008).

    Article  Google Scholar 

  18. Gruber, C. & Haimberger, L. Meteorol. Z. (in the press).

  19. Allen, R. J. & Sherwood, S. C. Utility of radiosonde wind data in representing climatological variations of tropospheric temperature and baroclinicity in the western tropical Pacific. J. Clim. 20, 5229–5243 (2007).

    Article  Google Scholar 

  20. Holton, J. R. An Introduction to Dynamic Meteorology (Academic, San Diego, 1992).

    Google Scholar 

  21. Pielke, R. A., Chase, T. N., Kittel, T. G. F., Knaff, J. A. & Eastman, J. Analysis of 200 mbar zonal winds for the period 1958–1997. J. Geophys. Res. 106, 27287–27290 (2001).

    Article  Google Scholar 

  22. Randel, W. J. The evaluation of winds from geopotential height data in the stratosphere. J. Atmos. Sci. 44, 3097–3120 (1987).

    Article  Google Scholar 

  23. Durre, I., Vose, R. S. & Wuertz, D. B. Overview of the integrated global radiosonde archive. J. Clim. 19, 53–68 (2006).

    Article  Google Scholar 

  24. Thompson, D. W. J. & Wallace, J. M. Annular modes in the extratropical circulation. Part I: Month to month variability. J. Clim. 13, 1000–1016 (2000).

    Article  Google Scholar 

  25. Scaife, A. J., Knight, J. R., Vallis, G. K. & Folland, C. K. A stratospheric influence on the winter NAO and North Atlantic surface climate. Geophys. Res. Lett. 32, doi:10.1029/2005GL023226 (2005).

  26. Raisanen, J. CO2-induced changes in the atmospheric angular momentum in CMIP2 experiments. J. Clim. 16, 132–143 (2003).

    Article  Google Scholar 

  27. Lorenz, D. J. & DeWeaver, E. T. Tropopause height and zonal wind response to global warming in the IPCC scenario integrations. J. Geophys. Res. 112, doi:10.1029/2006JD008087 (2007).

  28. Kalnay, E. et al. The NCEP/NCAR 40-year reanalysis project. Bull. Am. Meteorol. Soc. 77, 437–471 (1996).

    Article  Google Scholar 

  29. Cordero, E. C. & de F. Forster, P. M. Stratospheric variability and trends in models used for the IPCC AR4. Atmos. Chem. Phys. 6, 5369–5380 (2006).

    Article  Google Scholar 

  30. Randall, D. A. et al. 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, Cambridge, 2007).

    Google Scholar 

  31. GCOS. GCOS Reference Upper-Air Network (GRUAN): Justification, requirements, siting and instrument options. GCOS-112, WMO-TD 1379 (2007).

  32. GCOS. GCOS Implementation Plan for the Global Observing System for Climate in support of UNFCC. GCOS-92, WMO-TD 1219 (2004).

Download references


We acknowledge the individual modelling groups, the Program for Climate Model Diagnosis and Intercomparison and the WCRP’s Working Group on Coupled Modeling for their roles in making available the WCRP CMIP3 multimodel dataset. Support of this dataset is provided by the Office of Science, US Department of Energy. We also thank P. Thorne and L. Haimberger for providing key datasets.

Author information

Authors and Affiliations



R.J.A. initiated and conducted the project, carried out all data analysis and led the writing of the manuscript as part of his PhD thesis. S.C.S. advised on methods and interpretation.

Corresponding author

Correspondence to Robert J. Allen.

Supplementary information

Supplementary Information

Supplementary figures S1-S17 and table S1 (PDF 720 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Allen, R., Sherwood, S. Warming maximum in the tropical upper troposphere deduced from thermal winds. Nature Geosci 1, 399–403 (2008).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing