QBO Phase Synchronization in CMIP6 Historical Simulations Attributed to Ozone Forcing

Abstract Tropical stratospheric variability is investigated in ensembles of historical simulations performed by nine models for the sixth phase Coupled Model Intercomparison Project (CMIP6). Realizations from all feature a reasonable quasi‐biennial oscillation (QBO). Variability zonal mean winds at equator found to be coherent among realizations when model prescribes CMIP6 ozone forcing. No such coherence simulates ozone. The results an ensemble QBO signal with amplitude, depending on model, 50%–80% amplitude single realization same model. due synchronization phases, attributed protocol including Coherence using is, therefore, artificial and individual these are not completely independent.