The variability of the stratosphere plays a key role for many atmospheric phenomena. Examples include the dynamical two-way coupling between the stratosphere and troposphere during sudden stratospheric warming events, the transport of trace gases through the meridional circulation of the stratosphere, or the connection between the Quasi-Biennial Oscillation of the tropical stratosphere and the Madden-Julian Oscillation. This session is interested in all aspects of stratospheric circulation variability, including the mechanisms behind the vertical coupling between the stratosphere and troposphere in tropics and extratropics, the importance of stratospheric dynamics for explaining both short-term atmospheric weather and long-term climate variability, and the role of the stratospheric circulation for the chemical composition of the atmosphere. We welcome abstracts that study this problem from an observational, modelling, or theoretical viewpoint on all temporal and spatial scales.