Thinning heavens
European scientists have found evidence of ozone levels over the Arctic declining by about 50 per cent between the altitudes of 16 and 18 km (Nature, Vol 374, No 6522).
The Second European Stratospheric Arctic and Mid-latitude Experiment also revealed that ozone levels fell by about 0.7 per cent per day in parts of the polar vortex - a moving body of cold air found mostly show northern Europe.
The researchers claim that ozone over the middle latitudes in the northern hemisphere has decreased by more than 7 per cent in the last 15 years. However, further analysis is required to ascertain the Cause of the ozone loss, they add.