Scientists Underestimate Role of Ozone Hole in the Carbon Cycle
02.07.2009 - Water & Oceans, Other, Antarctic
A pluridisciplinary collaborative team of scientists has come together to develop a more accurate climate model that takes into account and assesses the Southern Ocean's ability to act as a carbon sink. This is the first time that the impact of the ozone hole on the oceanic carbon cycle has been simulated in a global climate model.
By absorbing almost 15% of anthropogenic carbon released every year, the Southern Ocean is one of the main sinks for atmospheric CO2. Basing themselves on the IPSL's coupled ocean/atmosphere model, which integrates the carbon cycle, the scientists developed a model that takes into account changes in the concentration of stratospheric ozone from 1975 until today. Two major phenomena have been brought to light in the Southern Ocean:
- reduction in CO2 intake (-10% between 1987 and 2004)
- an acceleration in acidification of high southern latitude ocean water
The upper atmosphere ozone hole interacts with greenhouse gases and the oceanic carbon cycle to create stronger westerly winds in the Southern Ocean which, in turn, leads to surface oceanic water being mixed with deep water that is rich in CO2. The end result is a limitation of the surface water's ability to absorb atmospheric carbon.
These results suggest that the climate models used until now have overestimated oceanic carbon intake and underestimated ocean acidification. They also underline the importance of taking ozone into account in future modeling.
