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Enhanced seasonal forecast skill following stratospheric sudden warmings


Advances in seasonal forecasting have brought widespread socio-economic benefits. However, seasonal forecast skill in the extratropics is relatively modest1, prompting the seasonal forecasting community to search for additional sources of predictability2,3. For over a decade it has been suggested that knowledge of the state of the stratosphere can act as a source of enhanced seasonal predictability; long-lived circulation anomalies in the lower stratosphere that follow stratospheric sudden warmings are associated with circulation anomalies in the troposphere that can last up to two months4,5. Here, we show by performing retrospective ensemble model forecasts that such enhanced predictability can be realized in a dynamical seasonal forecast system with a good representation of the stratosphere. When initialized at the onset date of stratospheric sudden warmings, the model forecasts faithfully reproduce the observed mean tropospheric conditions in the months following the stratospheric sudden warmings. Compared with an equivalent set of forecasts that are not initialized during stratospheric sudden warmings, we document enhanced forecast skill for atmospheric circulation patterns, surface temperatures over northern Russia and eastern Canada and North Atlantic precipitation. We suggest that seasonal forecast systems initialized during stratospheric sudden warmings are likely to yield significantly greater forecast skill in some regions.

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Figure 1: Surface climate response to SSWs.
Figure 2: Observed versus forecast 1,000 hPa NAM index.
Figure 3: Vertical profile of the mean NAM and of the CSS of the NAM.
Figure 4: The CSS of various variables.

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  1. Oldenborgh, G. J., van, Balmaseda, M., Ferranti, L., Stockdale, T. N. & Anderson, D. L. T. Evaluation of atmospheric fields from the ECMWF seasonal forecasts over a 15-year period. J. Clim. 18, 3250–3269 (2005).

    Article  Google Scholar 

  2. Kirtman, B. & Pirani, A. WCRP position paper on seasonal prediction. WCRP Informal Report, Vol. 3 (WCRP, 2008).

  3. NRC Assessment of Intraseasonal to Interannual Climate Prediction and Predictability (National Academies Press, 2010).

  4. Baldwin, M. P. & Dunkerton, T. J. Stratospheric harbingers of anomalous weather regimes. Science 294, 581–584 (2001).

    Article  Google Scholar 

  5. Thompson, D. W. J., Baldwin, M. P. & Wallace, J. M. Stratospheric connection to Northern Hemisphere wintertime weather: Implications for prediction. J. Clim. 15, 1421–1428 (2002).

    Article  Google Scholar 

  6. Gerber, E. P., Orbe, C. & Polvani, L. M. Stratospheric influence on the tropospheric circulation revealed by idealized ensemble forecasts. Geophys. Res. Lett. 36, L24801 (2009).

    Article  Google Scholar 

  7. Marshall, A. G. & Scaife, A. A. Improved predictability of stratospheric sudden warming events in an atmospheric general circulation model with enhanced stratospheric resolution. J. Geophys. Res. 115, D16114 (2010).

    Article  Google Scholar 

  8. Baldwin, M. P. et al. Stratospheric memory and skill of extended-range weather forecasts. Science 301, 636–640 (2003).

    Article  Google Scholar 

  9. Charlton, A. J., O’Neill, A., Stephenson, D. B., Lahoz, W. A. & Baldwin, M. P. Can knowledge of the state of the stratosphere be used to improve statistical forecasts of the troposphere? Q. J. R. Meteorol. Soc. 129, 3205–3224 (2003).

    Article  Google Scholar 

  10. Christiansen, B. Downward propagation and statistical forecast of the near-surface weather. J. Geophys. Res. 110, D14104 (2005).

    Article  Google Scholar 

  11. Siegmund, P. Stratospheric polar cap mean height and temperature as extended-range weather predictors. Mon. Weather Rev. 133, 2436–2448 (2005).

    Article  Google Scholar 

  12. Maycock, A. C., Keeley, S. P. E., Charlton-Perez, A. J. & Doblas-Reyes, F. J. Stratospheric circulation in seasonal forecasting models: Implications for seasonal prediction. Clim. Dynam. 36, 309–321 (2011).

    Article  Google Scholar 

  13. Mukougawa, H., Hirooka, T. & Kuroda, Y. Influence of stratospheric circulation on the predictability of the tropospheric Northern Annular Mode. Geophys. Res. Lett. 36, L08814 (2009).

    Article  Google Scholar 

  14. Scinocca, J. F., McFarlane, N. A., Lazare, M., Li, J. & Plummer, D. Technical note: The CCCma third generation AGCM and its extension into the middle atmosphere. Atmos. Chem. Phys. 8, 7055–7074 (2008).

    Article  Google Scholar 

  15. Thompson, D. W. & Wallace, J. M. Regional climate impacts of the Northern Hemisphere annular mode. Science 293, 85–89 (2001).

    Article  Google Scholar 

  16. Hardiman, S. C., Butchart, N., Hinton, T. J., Osprey, S. M. & Gray, L. J. The effect of a well resolved stratosphere on surface climate: Differences between CMIP5 simulations with high and low top versions of the Met Office climate model. J. Clim. 25, 7083–7099 (2012).

    Article  Google Scholar 

  17. Roff, G., Thompson, D. W. J. & Hendon, H. Does increasing model stratospheric resolution improve extended-range forecast skill? Geophys. Res. Lett. 38, L05809 (2011).

    Article  Google Scholar 

  18. Uppala, S. M. et al. The ERA-40 re-analysis. Q. J. R. Meteorol. Soc. 131, 2961–3012 (2005).

    Article  Google Scholar 

  19. Dee, D. P. et al. The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Q. J. R. Meteorol. Soc. 137, 553–597 (2011).

    Article  Google Scholar 

  20. Baldwin, M. P. & Thompson, D. W. J. A critical comparison of stratosphere–troposphere coupling indices. Q. J. R. Meteorol. Soc. 135, 1661–1672 (2009).

    Article  Google Scholar 

  21. Rayner, N. A. et al. Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res. 108, 4407 (2003).

    Article  Google Scholar 

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M.S. gratefully acknowledges funding by Environment Canada through a Grants and Contributions Agreement with the University of Toronto. We thank B. Merryfield, J. Fyfe and N. Gillett for their helpful comments.

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M.S., J.F.S. and V.V.K. designed the experiments. All authors interpreted the results and contributed to writing the paper.

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Correspondence to M. Sigmond.

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The authors declare no competing financial interests.

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Sigmond, M., Scinocca, J., Kharin, V. et al. Enhanced seasonal forecast skill following stratospheric sudden warmings. Nature Geosci 6, 98–102 (2013).

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