Overview of experiment design and comparison of models participating in phase 1 of the SPARC Quasi-Biennial Oscillation initiative (QBOi). - Butchart, Neal; Anstey, James A.; Hamilton, Kevin; Osprey, Scott; McLandress, Charles; Bushell, Andrew C.; Yoshio Kawatani; Lott, Francois; Scinocca, John; Stockdale, Tim; Bellprat, Omar; Braesicke, Peter; et al. (Geoscientific Model Development Discussions, 2017)