ESA technology tracking 'European' ozone hole
Scientists at the Netherlands KNMI working in cooperation with the European Space Agency (ESA) are tracking a mini ozone hole which is opening up over the North Atlantic ocean and heading for Europe. KNMI predicts that the hole, which is due to sweep from Greenland to southern Scandinavia over the next few days, will see ozone levels fall by 60 to 70 per cent from the seasonal average. The researchers have been able to observe the mini hole using KNMI's 'GOME fast delivery service'. This was developed under the ESA Data User programme, which harnesses data from the GOME instrument aboard the European remote sensing satellite ERS-2 and allows scientists to track the movements and growth of the hole in almost real time. Ozone helps to shield the Earth's surface from the Sun's harmful ultraviolet rays. Ankie Piters at KNMI said that although the mini ozone hole does not pose a significant threat, 'low ozone events over Europe are still of great interest. They seem to be caused mainly by unusual air currents in the atmosphere, not by chemical breakdown of ozone, which is what you see in the development of the Antarctic ozone hole.' The GOME spectrometer works by scanning the atmosphere below the flight path of the ERS-2 satellite, gathering sunlight backscattered by the atmosphere and reflected by the Earth's surface and analysing its spectrum from ultra-violet to infra-red. Different chemical groups absorb specific wavelengths of light, so their presence shows up as absorption lines on the GOME spectra. Europe is already preparing the next generation of satellite instruments to improve the monitoring of ozone and other key chemicals in the atmosphere. The SCIAMACHY instrument (scanning imaging absorption spectrometer for atmospheric cartography) on board ESA's environmental satellite Envisat will continue the work of the GOME series of measurements. ESA and EUMETSAT (the European organisation for the exploitation of meteorological satellites) are also preparing a series of three satellites (Metop) which will follow on from the work of the GOME instruments and providing at least ten years of ozone monitoring from space from 2003 onwards.