Arctic stratospheric ozone depletion and climate change
Large losses of Arctic stratospheric ozone have been observed during winter 2010/2011, exceeding observed losses during previous cold winters, characterized as the first Arctic Ozone Hole. Although in general Arctic ozone is expected to recover because of the reductions in ozone depleting substances as a result of the Montreal Protocol and its amendments, the observation that apparently the cold Arctic winters in the stratosphere have been getting colder raises some concern that Arctic ozone depletion may worsen over the next decades if the cooling trend continues while concentrations of ozone depleting substances remain sufficiently high. In the talk I will show satellite observations and model results of the 2010/2011 Arctic ozone loss and its sensitivity to a changing climate. Sensitivity calculations with our chemistry transport model with a prescribed further cooling of the stratosphere by 1K show locally in the Arctic near-complete ozone depletion over a large vertical extent. Our model calculations indicate that a continued cooling of the Arctic stratosphere could be sufficient to counterbalance the expected reduction in ozone depleting substances so that severe Arctic ozone depletion like in 2010/2011 or even worse may recur over the coming decades.
Created 2011-11-14 15:18:26 by Uwe Raffalski Last changed 2011-12-05 13:56:06 by Uwe Raffalski
