Satellite instrument helps tackle mysteries of ozone-eating clouds   Polar stratospheric clouds are often referred to as mother-of-pearl clouds because of their iridescent appearance. These clouds form in altitudes between 20 and 30 kilometres when temperatures drop to minus 80 degrees Celsius and play a vital role in ozone destruction.   10 years of ozone hole monitoring by GOME and SCIAMACHY   A view of Antarctica's mountain wave and nitric acid trihydrate (NAT) temperatures for 2003. Blue contours show the overall temperatures, while green contours show the NAT local formation. Release date: 22 February 2008