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QBO Changes in CMIP6 Climate Projections
Author(s) -
Butchart Neal,
Anstey James A.,
Kawatani Yoshio,
Osprey Scott M.,
Richter Jadwiga H.,
Wu Tongwen
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl086903
Subject(s) - stratosphere , coupled model intercomparison project , quasi biennial oscillation , climatology , atmospheric sciences , climate model , environmental science , climate system , climate change , geology , oceanography
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.