Ozone viewed in space with Earth below. Credit: studio023

Metop-A measures ozone hole over the Antarctic

3 October 2007 00:00 UTC

Ozone viewed in space with Earth below. Credit: studio023
Ozone viewed in space with Earth below. Credit: studio023

Metop-A satellite measures ozone hole over the Antarctic in October 2007.

Last Updated

09 May 2022

Published on

03 October 2007

By Diego Loyola (DLR-IMF) (DLR, Applied Remote Sensing Cluster)

Scientists at the Deutsche Zentrum für Luft- und Raumfahrt (DLR), the German Aerospace Center, continue the long-term monitoring of the evolution of the ozone hole by analysing data from the Global Ozone Monitoring Experiment 2 (GOME-2) instrument on board the Metop-A polar orbiting satellite.

The atmospheric data from GOME-2 measurements are derived by the DLR's Remote Sensing Technology Institute in Oberpfaffenhofen at the request of EUMETSAT. Initial validation of GOME-2 ozone data by ground measurements confirmed the high quality of the satellite data.

The DLR's German Remote Sensing Data Center (DFD) processes GOME-2 ozone data by combining it with models which describe meteorology, physics and atmospheric chemistry, allowing the mapping of the ozone layer and the prediction of ozone distribution. These models can provide additional information, such as the determination of chemical depletion of ozone; up-to-date ozone data and ozone depletion rates are available daily in near real time on the Internet at the World Data Centre for Remote Sensing of the Atmosphere, which is run by the DFD on behalf of the International Council of Scientific Unions. Animations of GOME-2 ozone and related constituents are produced operationally by DFD's GeoVisualizationCenter (GeoVIS). The ready-to-broadcast GOME-2 animations are available at the GOME-2 Ozone Forecast and Near-Real-Time Service.

The main cause of the depletion of the atmosphere's protective ozone layer is the release of chlorinated fluorocarbons. This depletion, which is most noticeable over the Arctic and Antarctic regions, is of particular environmental concern as the resulting increased levels of ultraviolet radiation can cause serious damage to human health, agriculture, forests and water ecosystems.

In 2007, the DLR noted a strong reversal in the spreading of the ozone hole in mid-September because of an unusual meteorological circulation in the south polar stratosphere. An unusually high intensity of planetary waves — which cause air circulation around the world — resulted in the thinning of the ozone layer, especially over the south Atlantic and South America. At the same time, the ozone level rose over Australia.

The 2007 ozone hole over the Antarctic was at its maximum size, twice as big as Europe, at the end of September. The ozone layer had thinned down to 220 Dobson units, a measure of atmospheric ozone, specifically ozone in the stratospheric ozone layer. The global average of the ozone layer is 300 Dobson units.

Total Ozone, Southern Hemisphere

Metop-A GOME-2 Ozone
Figure 1: Level-4 Total Ozone product from ROSE model based on GOME-2 Total Ozone retrievals, 3 Oct 2007

Level-3 Total Ozone product

Metop-A GOME-2 Ozone
Figure 2: Level-3 Total Ozone product, 3 Oct 2007
Figure 3: Total Ozone, 29 Aug 2007–01 Jan 2008