DynVar – Dynamical Variability

Activity leaders

Daniela Domeisen
ETH Zurich, Switzerland and University of Lausanne, Lausanne, Switzerland

Alexey Karpechko
Finnish Meteorological Institute, Helsinki, Finland

Team members

Committee members:  Edwin Gerber (DynVarMIP coordinator), Amy Butler, Natalia Calvo, Andrew Charlton-Perez, Marlene Kretschmer, Eun-Pa Lim, Michael Sigmond, Isla Simpson, and Shingo Watanabe

Ex-Officio Members: Marco Giorgetta, Paul Kushner, Elisa Manzini, Judith Perlwitz, Lorenzo Polvani, Fabrizio Sassi, Adam Scaife, Tiffany Shaw

Activity description

DynVar is an international working group on the modelling of the dynamics and variability of the stratosphere-troposphere system. DynVar focuses on the interactions between atmospheric variability, dynamics, and climate change, with a particular emphasis on the two-way coupling between the troposphere and stratosphere. To this end, DynVar promotes the development and use of a hierarchy of models ranging from simplified general circulation models to coupled atmosphere-ocean-sea-ice general circulation models, with the atmospheric component extending to above the stratopause.

The key questions addressed by the activity are:

  • How do dynamical processes contribute to persistent model biases in the mean state and variability of the atmosphere, including biases in the position, strength, and statistics of blocking events, storm tracks, and the stratospheric polar vortex?
  • How does the stratosphere affect climate variability at intra-seasonal, inter-annual, and decadal time scales?
  • What is the role of dynamics in shaping the climate response to anthropogenic forcings (e.g. global warming, ozone depletion) and how do dynamical processes contribute to uncertainty in future climate projections?
  • What is the role of stratosphere-troposphere coupling for extreme weather and climate events?

DynVar has been active in the assessment of stratospheric mean climate, variability, and change, as well as of the stratosphere-troposphere dynamical coupling in climate models participating in the latest set of climate projections, carried out under the fifth Coupled Model Inter-comparison Project (CMIP5). On discerning the role of the stratosphere on intraseasonal time scales, initiatives within DynVar have focused on the stratospheric seasonal prediction hindcasts produced as part of WGSIP’s Stratosphere Historical Forecast Project (SHFP). Ongoing activities are related to analysis of CMIP6 simulations, in particular those providing additional dynamical diagnostics as a part of DynVarMIP (Gerber and Manzini 2016).

Ongoing activities are related to analysis of CMIP6 simulations, in particular those providing additional dynamical diagnostics as a part of DynVarMIP (Gerber and Manzini 2016). More information about DynVarMIP, as well as its current status, can be found from DynVarMIP’s web-site: https://dynvarmip.github.io/.

The use of simplified models and more theoretical approaches to build the knowledge of two-way stratosphere-troposphere coupling is also an important component of the activity. DynVar is also extending its focus to tropospheric dynamics, storm tracks, jets, blocking, and their modes of variability, with the aim of reaching a comprehensive understanding of troposphere-stratosphere variability and change. Of particular focus is the understanding of the role of stratosphere-troposphere coupling and associated large-scale dynamical processes in generating extreme weather and climate events. These DynVar activities connect most closely to the WCRP Grand Challenge on Clouds, Circulation, and Climate Sensitivity and the Grand Challenge on Weather and Climate Extremes.

DynVar has links with other ongoing SPARC activities, including CCMI, Gravity WavesSNAP, S-RIP, and SOLARIS-HEPPA.

DynVar organises community workshops approximately every 3 years. The next workshop is planned for early 2023. Information about date and venue will follow.

Research Topics:

  • Intra-seasonal variability, including sudden stratospheric warmings and other extremes related to the polar vortex, extratropical and tropical wave coupling, annular modes, blocking and storm tracks
  • Troposphere-stratosphere circulation changes
  • ENSO, MJO and QBO interactions, tropical and extra-tropical teleconnections
  • Large-scale circulation and extreme events


Journal publications

Karpechko, A. Y., Afargan-Gerstman, H., Butler, A. H., Domeisen, D. I. V., Kretschmer, M., Lawrence, Z., et al., 2022: Northern hemisphere stratosphere-troposphere circulation change in CMIP6 models: 1. Inter-model spread and scenario sensitivity. Journal of Geophysical Research: Atmospheres, 127, e2022JD036992.

Abalos, M., N. Calvo, S. Benito-Barca, H. Garny, S. C. Hardiman, P. Lin, M. B. Andrews, N. Butchart, R. Garcia, C. Orbe, D. Saint-Martin, S. Watanabe, and K. Yoshida, 2021: The Brewer-Dobson circulation in CMIP6 models, Atmos. Chem. Phys., 21, 13571–13591.

Ayarzagüena, B., Charlton‐Perez, A. J.,Butler, A. H., Hitchcock, P., Simpson, I.R., Polvani, L. M., et al., 2020: Uncertainty in the response of sudden stratospheric warmings and stratosphere‐troposphere coupling to quadrupled CO2 concentrations in CMIP 6 models. Journal of Geophysical Research: Atmospheres, 125, e2019JD032345.

Calvo, N., M. Iza, M.M. Hurwitz, E.Manzini, C.Peña-Ortiz, A.H. Butler, C.Cagnazzo, S. Ineson, and C.I. Garfinkel, 2017: Northern Hemisphere Stratospheric Pathway of different El Niño flavors in Stratosphere-Resolving CMIP5 models. Journal of the Climate, 30 (12), 4351-4371

Gerber, E. P. and E. Manzini, 2016: The Dynamics and Variability Model Intercomparison Project (DynVarMIP) for CMIP6: assessing the stratosphere–troposphere system. Geosci. Model Dev., 9, 3413-3425

Kidston J., A. A.Scaife, Steven C. Hardiman, Daniel M. Mitchell, Neal Butchart, Mark P. Baldwin and Lesley J. Gray, 2015: Stratospheric influence on tropospheric jet streams, storm tracks and surface weather. Nat. Geosci., 8, 433-450

Barnes, E.A., N.W. Barnes and L.M. Polvani, 2014: Delayed Southern Hemisphere climate change induced by stratospheric ozone recovery, as projected by the CMIP5 models. J. Climate, 27, 852-867.

Gerber, E. P. and S.-W. Son, 2014: Quantifying the Summertime Response of the Austral Jet Stream and Hadley Cell to Stratospheric Ozone and Greenhouse Gases. J. Climate, 27, 5538-5559, doi: 10.1175/JCLI-D-13-00539.1

Lott, F. et al., 2014: Kelvin and Rossby-gravity wave packets in the lower stratosphere of some high-top CMIP5 models. JGR Atmos., 119, 2156–2173, doi: 10.1002/2013JD020797

Manzini, E. et al., 2014: Northern winter climate change: Assessment of uncertainty in CMIP5 projections related to stratosphere-troposphere coupling. JGR Atmos., 119, doi: 10.1002/2013JD021403

Neely, R.R.,  D.R. Marsh, K.L. Smith, S.M. Davis and L.M. Polvani, 2014: Biases in Southern Hemisphere climate trends induced by coarsely specifying the temporal resolution of stratospheric ozone. Geophys. Res. Lett., 41, doi:10.1002/2014GL061627

Scaife, A. A., et al., 2014: Predictability of the quasi-biennial oscillation and its northern winter teleconnection on sea- sonal to decadal timescales. Geophys. Res. Lett., 41, 1752–1758, doi:10.1002/ 2013GL059160.

Seviour W.J.M., S.C. Hardiman, L.J. Gray, N. Butchart, C. MacLachlan and A.A. Scaife, 2014: Skillful seasonal prediction of the Southern Annular Mode and Antarctic ozone. J. Clim., 27, 7462-7474, DOI: 10.1175/JCLI-D-14-00264.1.

Shaw, T. A., J. Perlwitz, O. Weiner, 2014: Troposphere-stratosphere coupling: Links to North Atlantic weather and climate, including their representation in CMIP5 models. J. Geophys. Res., 10.1002/2013JD021191

Simpson, I.R., T.A. Shaw, and R. Seager, 2014: A Diagnosis of the Seasonally and Longitudinally Varying Midlatitude Circulation Response to Global Warming. J. Atmos. Sci., 71, 2489-2514, DOI: 10.1175/JAS-D-13-0325.1

Kawatani, Y., and K. Hamilton, 2013: Weakened stratospheric quasibiennial oscillation driven by increased tropical mean upwelling. Nature, 497, doi:10.1038/nature12140 See also corrigendum.

Hardiman, S.C., N. Butchart, and N. Calvo, 2013: The morphology of the Brewer–Dobson circulation and its response to climate change in CMIP5 simulations. Q.J.R. Meteorol. Soc., DOI: 10.1002/qj.2258

Charlton-Perez, A. J., M. Baldwin, T. Birner, R.X. Black, A.H. Butler, N. Calvo, N.A. Davis, E.P. Gerber, N. Gillett, S. Hardiman, J. Kim, K. Krüger, Y.-Y. Lee, E. Manzini, B.A. McDaniel, L. Polvani, T. Reichler, T.A. Shaw, M. Sigmond, S.-W. Son, M. Toohey, L. Wilcox, S. Yoden, B. Christiansen, F. Lott, D. Shindell, S. Yukimoto, S. Watanabe, 2013: On the lack of stratospheric dynamical variability in low-top versions of the CMIP5 models. J. Geophys. Res. Atmos., 118, 2494–2505, doi:10.1002/jgrd.50125

Reichler, T., J. Kim, E. Manzini, and J. Kröger, 2012: A stratospheric connection to Atlantic climate variability. Nature Geoscience, Letters, 5, 783-787. DOI 10.1038/ngeo1586.

Gerber, E.P., A. Butler, N. Calvo, A. Charlton-Perez, M. Giorgetta, E. Manzini, J. Perlwitz, L. M. Polvani, F. Sassi, A.A. Scaife, T. A. Shaw, S.-W. Son, S. Watanabe, 2012: Assessing and Understanding the Impact of Stratospheric Dynamics and Variability on the Earth System. Bulletin of the American Meteorological Society 93: 845-859.

SPARC activity updates

APARC newsletter No. 62, 2024, pp. 12-16: APARC Dynvar & SNAP Workshop: The Role of Atmospheric Dynamics for Climate and Extremes, by P. Hitchcock et al.

SPARC Newsletter No. 41, 2013, p. 40: Report on the 3rd SPARC DynVar Workshop on Modelling the Dynamics and Variability of the Stratosphere-Troposphere System, by E. Manzini et al.

SPARC Newsletter No. 36, 2011, p. 19: Report on the SPARC DynVar Workshop 2 on Modelling the Dynamics and Variability of the Stratosphere-Troposphere System, by E. Manzini et al.

SPARC Newsletter No. 32, 2009, p. 13: SPARC Dynamics and Variability Project (DynVar): Plans and Status, by P.J. Kushner et al.

SPARC Newsletter No. 29, 2007, p. 9: The SPARC DynVar Project: A SPARC Project on the Dynamics and Variability of the Coupled Stratosphere-Troposphere System, by P.J. Kushner et al.

Website for further information