Climate and Ozone

As the sun returns to Antarctica, it heralds the beginning of the fast and rapid destruction of ozone above the South Pole. The annual ozone 'hole' has now begun to form above Antarctica, as illustrated by these NASA maps, compiled daily from data gathered by satellite-borne instruments.

Land-based Dobson spectrophotometers are being used to ground-proof satellite data, and one of about 150 such instruments worldwide is housed in a small domed building at the National Institute of Water and Atmosphere research station at Lauder, in Central Otago. The Lauder team also regularly releases balloons (left) that carry ozone-detecting instruments into the high atmosphere.

Climate modeller Olaf Morgenstern (pictured below) tells Veronika Meduna that stratospheric ozone depletion is thought to dominate recent Southern-Hemisphere climate change because some models suggest that the formation of the ozone hole has caused precipitation regimes to move poleward. However, he says these models have shortcomings and he has been working on a new-generation model which incorporates both ozone chemistry and interactive ocean processes to understand how climate change and ozone depletion influence each other, and which impacts these interactions are having on global wind and ocean circulation systems. 

In this feature, Olaf Morgenstern explains how climate change could affect the rate of recovery of the ozone layer, and how, in turn, some of the substances used to replace the original ozone-depleting chemicals will contribute to climate change because they are much more potent greenhouse gases than carbon dioxide. His Marsden-funded model will be used to project how long-lived greenhouse gases and ozone recovery will affect Southern Hemisphere and New Zealand climate.

The Lauder team has also previously featured in this Our Changing World programme.