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News  Thanks to ESA, KNMI offers a UV forecasting Service
A unique new service which harnesses satellite data to powerful high-speed computing could soon lead to much improved weather forecasts and help make basking in the sun a lot safer. The "fast ozone profile" service developed by the Royal Netherlands Meteorological Institute (KNMI) within the ESA Data User Programme is a world first. It can deliver a three-dimensional map of ozone in the atmosphere worldwide within a few hours.
What matters to sunbathers is the total amount of ozone above their heads. But the new service is more sophisticated still. Rather than simply calculating the amount of ozone in a tower of air reaching from ground to space, the new service can plot a profile of the density of ozone at various altitudes.
"Three years ago, most people thought that this could not be feasible," remembers ESA’s Claus Zehner, who extended the ERS ground segment to provide GOME measurements very fast to KNMI for the development of this new service to users. "The big challenge is the computation," Ronald van der A explains. "To calculate total ozone, you’re using only part of the spectrum of light scattered back by the Earth’s atmosphere. But to generate the profile, you look at a much wider spectrum, each segment of which corresponds to a ‘backscattering layer’ at a particular altitude in the atmosphere. Again, in itself this is not such a big task - the real breakthrough is to be able to extract this profile information from the data in near real-time. We can publish the profiles with three hours of the data being gathered."
Although it still takes three days to cover the global surface, the near-real-time processing allows a complete global picture to be made available in the same timeframe, which is a major advance over any previous efforts. “Equally”, adds Ronald van der A, "because we can see events developing quickly, if we spot a hole appearing, we can alert local scientists who can then monitor the event hour by hour using equipment carried aboard specially-launched balloons, called sondes."
To take a closer look before you decide whether to apply factor 15 or factor 50 sunblock, go to: Ozone profiles on-line: UV-index forecast on-line: Notes for editors GOME is the Global Ozone Monitoring Experiment aboard the European Remote-Sensing satellite, ERS-2, launched in 1995 and continuing to make an important contribution to environmental monitoring and our understanding of the physical and chemical processes underlying Earth systems, on the global and local scale alike. SCIAMACHY – the SCanning Imaging Absorption Spectrometer for Atmospheric CartograpHY, is one of the 10 instruments aboard ESA’s new environmental satellite, Envisat, ready for launch this summer.
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Measuring the ozone hole with ERS/GOME (http://television.esa.int/photos/ozone2000.mpg)