Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

American Geophysical Union

30.06.2006
The Antarctic ozone hole will not disappear before 2068, nearly 20 years later than previously estimated, according to scientists using a new computer model. The ozone hole is caused by chlorine and bromine gases that destroy ozone in the stratosphere (an upper layer of Earth's atmosphere) during the southern hemisphere springtime.

The gases come from human-produced chemicals such as chlorofluorocarbons (CFCs). The Montreal Protocol, an international agreement adopted in 1987, limited the production of ozone-depleting substances. Amendments in 1990 and 1992 completely eliminated legal production and use of most of these chemicals, although there will be continued emissions from previously produced and stored quantities of those chemicals that have not been destroyed or recycled.

Researchers from NASA, the National Oceanic and Atmospheric Administration (NOAA), and the National Center for Atmospheric Research (NCAR) have simulated the ozone hole in a new math- based computer model. They used estimates of chlorine and bromine levels over Antarctica from NASA and NOAA satellite observations, NOAA ground-level observations, NCAR air-based observations taken from airplanes, and the temperature of the Antarctic stratosphere in late spring, when the ozone hole begins to form.

The model accurately reproduced the ozone hole area in the Antarctic stratosphere over the past 27 years. The researchers then made projections of ozone-depleting substances in the future, leading to their prediction that the ozone hole will recover in 2068, not in 2050, as previously estimated. Their findings will be published 30 June in Geophysical Research Letters, a journal of the American Geophysical Union.

"The Antarctic ozone hole is the poster child of ozone loss in our atmosphere," said lead author Paul Newman, a research scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Over areas that are farther from the poles like Africa or the U.S., the levels of upper atmospheric ozone are only three to six percent below natural levels. But, over Antarctica, ozone is 70 percent lower in the spring. This new method allows us to more accurately estimate ozone-depleting gases over Antarctica, and how they will decrease over time, improving the ozone hole."

The researchers also show that the ozone hole has not yet started to significantly shrink, which they predict will not occur until approximately 2018. They also concluded that greenhouse gas- forced climate change will have only a small impact on the Antarctic stratosphere and recovery of the ozone hole.

The upper ozone layer is important because it blocks 90-99 percent of the Sun's ultraviolet radiation from making contact with Earth's surface. This solar radiation can cause skin cancer and genetic and eye damage, and it can impact marine life.

"My job is to track ozone-depleting CFCs around the globe on a weekly basis," said Steven Montzka, a research chemist in the Global Monitoring Division at NOAA's Earth Systems Research Laboratory in Boulder, a co-author of the paper. "We make calculations with that information to determine how gases containing chlorine and bromine that have life spans in the atmosphere as long as 100 years are affecting ozone. This new prediction model is a very useful step forward to refining our understanding of ozone hole recovery time scales."

Harvey Leifert | American Geophysical Union
Further information:
http://www.agu.org

More articles from Earth Sciences:

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

nachricht Canadian glaciers now major contributor to sea level change, UCI study shows
15.02.2017 | University of California - Irvine

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>