Ozone Depletion and Changes in the Ventilation of the Southern Oceans

Surface westerly winds in the Southern Hemisphere have intensified over the past few decades, primarily in response to the formation of the Antarctic ozone hole. Here, we use oceanic measurements of CFC-12 made in the early 1990s and mid- to late-2000s to show large-scale coherent changes in the transport of surface waters into the interior (“ventilation”) of the southern oceans. In particular, there is a decrease in the age of subtropical subantarctic mode waters and an increase in the age of circumpolar deep waters. This suggests that the formation of the Antarctic ozone hole has caused large-scale coherent changes in the ventilation of the southern oceans. The possible mechanisms involved with this connection will be discussed, as well as the possible impact on the oceanic uptake of heat and carbon.