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 the stratosphere. To this end, DynVar promotes the development and use of coupled atmosphere-ocean-seaice 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 atmospheric circulation response to anthropogenic forcings (e.g. global warming, ozone depletion) and how do dynamical processes contribute to uncertainty in future climate projections?
Activities within DynVar connect most closely to the WCRP Grand Challenge on Clouds, Circulation, and Climate Sensitivity.