Premium
Quantifying uncertainty in future Southern Hemisphere circulation trends
Author(s) -
Watson Peter A. G.,
Karoly David J.,
Allen Myles R.,
Faull Nicholas,
Lee David S.
Publication year - 2012
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 - 10.1029/2012gl054158
Subject(s) - climatology , stratosphere , atmospheric sciences , environmental science , ozone depletion , ozone , troposphere , greenhouse gas , ozone layer , northern hemisphere , southern hemisphere , climate change , polar vortex , climate model , atmospheric circulation , polar night , atmosphere (unit) , meteorology , geology , geography , oceanography
The Antarctic polar night jet has intensified during spring in recent decades due to stratospheric ozone depletion and rising greenhouse gas (GHG) concentrations and this has had substantial effects on the region's climate. GHG concentrations will rise over the 21st century whereas stratospheric ozone is expected to recover and there is uncertainty in future southern hemisphere (SH) circulation trends. We examine sensitivity to the physics parameterisation of the 21st century SH circulation projection of a coupled atmosphere‐ocean General Circulation Model and the sensitivity of the contribution from stratospheric ozone recovery. Different model parameterizations give a greater range of future trends in the position of the tropospheric jet than has been found in previous multi‐model comparisons. Ozone recovery causes a weakening and northward shift of the DJF tropospheric jet. Varying the physics parameterization affects the zonal wind response to ozone recovery of the SON stratosphere by ∼10% and that of the DJF troposphere by ∼25%. The projected future SAM index changes with and without ozone recovery and the SAM index response to ozone recovery alone are found to be strongly positively correlated with projected 21st century global warming.