Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

QBO Changes in CMIP6 Climate Projections

TitleQBO Changes in CMIP6 Climate Projections
Publication TypeJournal Article
Year of Publication2020
JournalGeophysical Research Letters
Volume47
Number7
Abstract / Summary

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 urn:x-wiley:grl:media:grl60277:grl60277-math-0001% to urn:x-wiley:grl:media:grl60277:grl60277-math-0002 % to urn:x-wiley:grl:media:grl60277:grl60277-math-0003% 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.

URLhttp://dx.doi.org/10.1029/2019gl086903
DOI10.1029/2019gl086903
Journal: Geophysical Research Letters
Year of Publication: 2020
Volume: 47
Number: 7
Publication Date: 04/2020

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 urn:x-wiley:grl:media:grl60277:grl60277-math-0001% to urn:x-wiley:grl:media:grl60277:grl60277-math-0002 % to urn:x-wiley:grl:media:grl60277:grl60277-math-0003% 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.

DOI: 10.1029/2019gl086903
Citation:
Butchart, N, J Anstey, Y Kawatani, S Osprey, J Richter, and T Wu.  2020.  "QBO Changes in CMIP6 Climate Projections."  Geophysical Research Letters 47(7).  https://doi.org/10.1029/2019gl086903.