The circulation of the stratosphere significantly impacts tropospheric weather and climate. Key phenomena, including the stratospheric polar vortex, the Brewer-Dobson circulation, and the Quasi-Biennial Oscillation, are particularly influential. Variations in these phenomena modulate the propagation of atmospheric waves, exert a dynamical downward influence on the troposphere, and facilitate the transport of climatically important chemical constituents. Understanding, observing, and accurately simulating the dynamics of the stratosphere are therefore essential for predicting changes in tropospheric weather and climate. This session focuses on the causes and consequences of variations in the stratospheric circulation, including its natural and anthropogenic drivers, chemical transport and mixing processes, and its role for the prediction of weather and climate. We welcome abstracts that address these topics from observational, modeling, or theoretical perspectives across all scales.