Over the last two decades of the 20th century the southern hemisphere stratospheric stationary wave amplitude increased in late spring and early summer. Using the results from several chemistry-climate models, L. Wang and co-authors separate the effects of anthropogenic forcing from ozone-depleting substances (ODSs) and greenhouse gases (GHGs) on these changes. The increase in amplitude is reproduced in simulations with changing ODSs, a response related to changes in the strength and timing of the breakdown of the polar vortex. GHGs have little impact on the simulated stationary wave amplitude, but are projected to induce an eastward shift of the waves, which is linked to the strengthening of the subtropical jet. The full abstract can be found here.
