Biodiversity / Food / Water

December 30, 2007


2007 Ozone Hole Looms over Antarctica, as for the Past Decade

Keywords: Ecosystems / Biodiversity University / Research institute 

The Antarctic ozone hole appeared in mid-August in 2007 and was almost the size of the Antarctic continent in mid-September, the Japan Meteorological Agency (JMA) announced on September 13, 2007. The JMA analyzed satellite data from the National Aeronautics and Space Administration (NASA).

The ozone hole over Antarctica usually forms in late August, developing to its largest size during September and October. It disappears around November or December as austral summer approaches. The concentrations of ozone-depleting substances in the atmosphere peaked in the late 1990s and have since hovered at high levels. According to the JMA, the ozone hole in 2007 is expected to be about the same size as the average over the past 10 years, as the area of stratospheric cold air mass (below minus 78 degrees Celsius) over the Antarctic region, which accelerates ozone destruction, has not yet reached the size of last year's, and thus the ozone hole is unlikely to develop to the record size seen in 2006.

The "Montreal Protocol on Substances that Deplete the Ozone Layer" celebrated its 20th anniversary on September 16, 2007. During this period, international efforts have seen recognizable progress to reverse ozone depletion, as evidenced by the JMA's report that confirmed the decline of ozone-depleting chlorofluorocarbon-11 in the atmosphere, and the absence of an increase in ozone hole size since 2000. However, scientists predict that the large amounts of ozone-depleting substances still present in the atmosphere will continue to cause the hole in the ozone layer for the next few decades.
- Global Ozone Layer Still in Danger Despite Slight Improvements in Northern Hemisphere since 1990s (Related JFS article)
- Total Ozone Over Japanese Antarctic Station Hits New Low (Related JFS article)
- Agency Report Shows Global Climatic Changes in 2006 (Related JFS article)

Posted: 2007/12/30 12:00:05 PM
Japanese version