Ozone layer depletion leveling off(21197; consistent with earlier studies b...)

Date:9/21/2009

21197;, consistent with earlier studies based on data from satellites and ground networks. A clear statistically significant change of trend can be seen around 1997. The small increase (of 0.8𔂿.4% per decade) observed thereafter, from 1997 to 2008, is however not yet statistically different from a zero trend. We hope to see a significant recovery of (upper stratospheric) ozone in the next years using longer, extended satellite time-series," Urban said.

The thinning of the ozone layer is caused by chemicals such as human-produced bromine and chlorine gases that have long lifetimes in the atmosphere. The Montreal Protocol (1987) was introduced to regulate and phase out the production of these substances. Its effect can clearly be seen in the satellite observations of ozone and these chemicals.

Using SCIAMACHY data in limb-viewing observation mode from 2002 to 2008, Franois Hendrick from the Belgian Institute for Space Aeronomy (BIRA/IASB) and his colleagues from the University of Bremen performed a trend analysis of bromine monoxide (BrO) in the stratosphere. BrO is a highly efficient catalyst in ozone destruction. The results show a negative trend in BrO abundance in the stratosphere during this period, marking the first time a decline in stratospheric bromine has been reported from a spaceborne observation.

"The good agreement with ground-based observations at high and mid-latitudes show that SCIAMACHY limb data can be used for stratospheric BrO trend monitoring. These findings provide strong evidences that the Montreal Protocol restrictions on brominated substances have now reached the stratosphere," Hendrick said.

Having access to these atmospheric satellite data over long periods is important for scientists to identify and analyse long-term trends and changes. In addition to monitoring ozone trends, scientists will continue to monitor ozone-depleting substances that were phased out under the Montreal Protocol but con
'/>"/>

Contact: Mariangela D'Acunto mariangela.dacunto@esa.int 39-069-418-0856 European Space Agency Source:Eurekalert

0 GOOD

Page: 1 2 3
Related biology news :

1. Houseplants cut indoor ozone
2. Ozone, nitrogen change the way rising CO2 affects Earths water
3. Ozone depletes oil seed rape productivity
4. Ozone depletes oil seed rape productivity
5. Oh, my aching back: Give me a shot of ozone
6. European satellites provide new insight into ozone-depleting species
7. Research finds new cause of ozone wheezing and potential treatments
8. Surface-level ozone pollution set to reduce tree growth 10 percent by 2100
9. Wildfires cause ozone pollution to violate health standards, new study shows
10. Alternatives to ozone-depleting pesticide studied
11. Ozone hole recovery may reshape southern hemisphere climate change