The objective of QBOi is to improve the fidelity of tropical stratosphere variability in present-day GCMs. This will be achieved by: (1) evaluating past, present-day and future modelled QBO variability, and (2) soliciting the participation of modelling groups to design numerical experiments to explore and understand the sensitivity dependencies of tropical stratosphere variability in current GCMs. Examples of these dependencies include model details such as vertical resolution, gravity wave parameterizations, etc. Our intention is that this will provide guidelines and improved understanding of how to simulate a realistic QBO for the correct reasons, informing models contributing to future CMIP experiments and for numerical weather forecasters.
QBOi is focussed on modelling studies, but benefits from other SPARC activities, such as: Gravity Waves (for constraining the gravity wave parameterizations used within GCMs) and the Data Assimilation Working Group project S-RIP: SPARC Reanalysis/Analysis Intercomparison Project (e.g. for providing tropical wave climatologies). Output from QBOi will also benefit programmes such as the Working Group for Numerical Experimentation (evaluating process uncertainty), the Working Group on Seasonal to Interannual Prediction (identifying pathways for predictability), and within SPARC, CCMI (tracer transport), DynVar (stratosphere-troposphere coupling).
- Osprey, S. M., N. Butchart, J. R. Knight, A. Scaife, K. Hamilton, J. A. Anstey, V. Schenzinger, and C. Zhang, 2016: An unexpected disruption of the atmospheric quasi-biennial oscillation. Science, 08 Sep 2016, DOI: 10.1126/science.aah4156
- Rajendran K., I. M. Moroz, P. L. Read and S. M. Osprey, 2016: Synchronisation of the equatorial QBO by the annual cycle in tropical upwelling in a warming climate. Q. J. R. Meteorol. Soc., DOI: 10.1002/qj.2714
- Hamilton, K., S. Osprey, and N. Butchart, 2015: Modeling the stratosphere’s “heartbeat,” EOS, 96, doi:10.1029/2015EO032301.
SPARC activity updates:
- SPARC newsletter No. 45, 2015, p. 19: Report on the 1st QBO Modelling and Reanalyses Workshop, by Anstey, J., K. Hamilton, S. Osprey, N. Butchart, and L. Gray/li>