Australia: The Land Where Time Began

A biography of the Australian continent 

Antarctic Circumpolar Current - Response to recent Climate change

The westerlies, the prevailing winds between 30^oS and 60^oS, in the Southern Hemisphere have been observed to have intensified significantly over the past decades. Climate scenarios have predicted that this trend of intensification will continue for the 21st century. According to Boning et al. the response of the Antarctic Circumpolar Current and the carbon sink in the Southern Ocean to wind stress changes and fluxes of surface buoyancy is being debated. In this study Boning et al. have analysed the Argo network of profiling floats, as well as historical oceanographic data, to detect coherent warming and freshening trends, on a hemispheric scale, that extend to below 1,000 m depth. Changes in the properties of the water masses making up the Antarctic Circumpolar Current are in part related to the warming and freshening, which is consistent with anthropogenic changes of the fluxes of heat and freshwater that have been suggested by climate models. Boning et al. say they have not detected any increase in the tilt of the surfaces of equal density across the Antarctica Circumpolar Current, which contradicts the results of the studies using coarse-resolution models. It is implied by the results of this study that the transport in the Antarctica Circumpolar Current and meridional overturning in the Southern Ocean are insensitive to decadal changes in wind stresses.

Sources & Further reading

1. Boning, C. W., A. Dispert, M. Visbeck, S. Rintoul, and F. U. Schwarzkopf. "Response of the Antarctic Circumpolar Current to Recent Climate Change." Nature Geosci. 1 (// 2008): 864-69.