QBO changes in CMIP6 climate projections
Date
2020
Authors
Butchart, Neal
Anstey, James A.
Kawatani, Yoshio
Osprey, Scott M.
Richter, Jadwiga H.
Wu, Tongwen
Journal Title
Journal ISSN
Volume Title
Publisher
Geophysical Research Letters
Abstract
Phase 6 of the Coupled-Model Intercomparison Project (CMIP6) is the first in which a significant number of models include a well-resolved stratosphere. Changes in equatorial stratospheric variability in historical and Shared Socioeconomic Pathways (SSPs) scenario simulations are investigated in 10 models with realistic quasi-biennial oscillations (QBO). All project a weakening of the QBO throughout the stratosphere for SSP370 and SSP585 scenarios and for 1960 to 2010. The weakening is strongest in the lower stratosphere, ranging from 5.8 ± 0.5% to 4.3 ± 0.5% to 2.0 ± 0.5% per decade at 50 hPa for SSP585, SSP370, and historical simulations, respectively. At 20 hPa a weakening of both westward and eastward phases contributes though the weakening eastward phase is only seen in 7 of the 10 models. Similar robust weakening occurs for the temperature QBO, but only from 30 hPa upward. In both scenarios the QBO period decreases in 7 of the 10 models.
Description
Keywords
Canadian Centre for Climate Modelling and Analysis (CCCma)
Citation
Butchart, N., Anstey, J., Kawatani, Y., Osprey, S., Richter, J. H., & Wu, T. (2020). QBO changes in CMIP6 climate projections. Geophysical Research Letters, 47(7). https://doi.org/10.1029/2019gl086903