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
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The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
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The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
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Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
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The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
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