The Impact of Stratospheric Ozone Recovery on the Southern Hemisphere Westerly Jet
S.-W. Son,1*
L. M. Polvani,1,2
D. W. Waugh,3
H. Akiyoshi,4
R. Garcia,5
D. Kinnison,5
S. Pawson,6
E. Rozanov,7,8
T. G. Shepherd,9
K. Shibata10
In the past several decades, the tropospheric westerly winds in the Southern Hemisphere have been observed to accelerate on the poleward side of the surface wind maximum. This has been attributed to the combined anthropogenic effects of increasing greenhouse gases and decreasing stratospheric ozone and is predicted to continue by the Intergovernmental Panel on Climate Change/Fourth Assessment Report (IPCC/AR4) models. In this paper, the predictions of the Chemistry-Climate Model Validation (CCMVal) models are examined: Unlike the AR4 models, the CCMVal models have a fully interactive stratospheric chemistry. Owing to the expected disappearance of the ozone hole in the first half of the 21st century, the CCMVal models predict that the tropospheric westerlies in Southern Hemisphere summer will be decelerated, on the poleward side, in contrast with the prediction of most IPCC/AR4 models.
1 Department of Applied Physics & Applied Mathematics, Columbia University, New York, NY 10027, USA.
2 Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA.
3 Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
4 National Institute for Environmental Studies, Tsukuba, Japan.
5 National Center for Atmospheric Research (NCAR), Boulder, CO 80325, USA.
6 NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA.
7 Institute for Atmospheric and Climate Sciences/Eidgenössische Technische Hochschule (ETH), Zurich, Switzerland.
8 Physical Meteorological Observatory, World Radiation Center, Davos, Switzerland.
9 Department of Physics, University of Toronto, Toronto, Canada.
10 Meteorological Research Institute, Tsukuba, Japan.
* To whom correspondence should be addressed. E-mail: sws2112{at}columbia.edu
