Transient Responses of the Southern Ocean to Climate Change Seminar

Circulation in the Southern Ocean is driven by a combination of wind and heat/freshwater fluxes, which conspire to generate both the Antarctic Circumpolar Current and the meridional overturning circulation (both moderated by a vigorous eddy field). Climate change is likely to cause both both warming and freshening in this region, as well as enhancing wind stress. Disentangling the individual effects that each of these surface forcings may have on individual components of the circulation is proving a difficult task. In this talk I will show recent progress from idealised numerical models which will be used to argue that:
(a) the sensitivity of the overturning circulation response to eddies differs from the circumpolar transport; and
(b) the abyssal overturning cell is weakening in response to a combination of freshening and warming.
Applying these results to recent analyses of the CMIP-5 suite of simulations allows us to further constrain future Southern Ocean responses to climate change.