Upper Atmosphere Research Satellite accuracy and spatial resolution, and hence to study the structure and dynamics of the region, (ii) To investigate the distribution and variability of water vapour in the middle atmosphere, to determine its role in the atmospheric general circulation, and its sources and sinks in the middle atmosphere, (iii) To measure the global distribution of oxides of nitrogen and hence to investigate their origins and their roles in catalytic cycles which control the amount of ozone in the stratospheric ozone layer. It also made extensive observations of volcanic aerosols and polar stratospheric clouds in the middle atmosphere. The instrument operated from
Ozone depletion from the 250 recorded over central Siberia. It is predicted that the thinning layer would affect parts of Scandinavia and Eastern Europe on March 30–31. On October 2, 2011, a study was published in the journal "Nature", which said that between December 2010 and March 2011 up to 80 percent of the ozone in the atmosphere at about above the surface was destroyed. The level of ozone depletion was severe enough that scientists said it could be compared to the ozone hole that forms over Antarctica every winter. According to the study, "for the first time, sufficient loss occurred to