Satellite instruments monitor the ozone layer, then the data are used to create images that depict the amount of stratospheric ozone. The blue and purple colors are where there is the least ozone, and the greens, yellows, and reds are where there is more ozone.The size of the hole in stratospheric ozone that develops over Antarctica at this time each year appears to have stabilized, according to satellite observations analyzed by various agencies around the world. Matthew Tulley from Australia’s Bureau of Meteorology says the hole has begun to show signs of healing because of the international agreement to phase out the production of ozone-depleting chemicals in the 1987 Montreal Protocol. Recent observations indicate that the level of ozone-depleting substances has decreased by 4 percent since 2001.
