The Quasi-Biennial Oscillation (QBO) is the main source of year-to-year variability in the tropical stratosphere with far reaching teleconnections to other parts of the climate system from extratropical variability to tropical convection. Historically it has exhibited a remarkably regular period of ~28 months, but recent, unprecedented disruptions indicate this periodicity may be fragile. It has long been recognized that radiative and dynamical feedbacks from stratospheric ozone can impact the QBO but a clear mechanistic description is still lacking. Moreover, simulating a realistic QBO in climate models is still challenging and many numerical models only include a simplified version by nudging their tropical winds to observations.The ozone feedback on the QBO has been examined mainly in the context of recent historical climate, with one recent study on the future changes in response to an increase in carbon dioxide. A review of the literature reveals large uncertainties in the magnitude of the ozone feedback on both the QBO period and amplitude. A new international model intercomparison project, QUOCA, has recently been launched to study ozone–QBO feedbacks with data expected by the end of 2024.
The main aim of this team is to use high-resolution satellite observations of tropical stratospheric temperature and composition to assess the representation of ozone-QBO feedbacks and associated dynamical processes in these new model runs.
The outcome of this activity will improve our understanding of the interactions between composition and the QBO, contributing to improving the fidelity of future model projections of the QBO and its teleconnections.
If you are interested in this project or the QUOCA model runs, please feel free to get in touch with us.
The proposal for this project can be found here.