Measurements with ground based instruments and with balloons show early signs of ozone depletion in several areas, according to the World Meteorological Organization’s Antarctic Ozone Bulletin – the first of the 2013 series.
As the sun returns to Antarctica after the polar night, ozone destruction will speed up. It is still too early to give a definitive statement about the development of this year's ozone hole and the degree of ozone loss that will occur. This will, to a large extent, depend on the meteorological conditions. However, the temperature conditions and the extent of polar stratospheric clouds so far indicate that the degree of ozone loss in 2013 will be similar to that observed in 2011 and larger than in 2010 and 2012, according to the Bulletin.
The meteorological conditions in the Antarctic stratosphere found during the austral winter (June-August) set the stage for the annually recurring ozone hole, which is expected to continue as long as the stratosphere contains an excess of ozone depleting substances. As stated in the Executive Summary of the 2010 edition of the WMO/UNEP Scientific Assessment of Ozone Depletion, severe Antarctic ozone holes are expected to continue during the next couple of decades.
WMO’s Global Atmosphere Watch Program and its network of scientific stations in some of the world’s most inhospitable terrain will use ozone observations from the ground, from balloons and from satellites together with meteorological data to monitor developments during the coming weeks and months.