Satellite image of the distribution of stratospheric ozone over the Arctic on 12th March 2019. Ozone layer thicknesses are colour coded from black (lowest) through blue, green, yellow and red to pink (highest). The ozone layer's thickness over the Arctic fluctuates from season to season and from year to year. The Antarctic has had a constant decline in ozone and its hole is greater than the Arctic hole. The amount of ozone depleting substances have decreased from peak levels in 2000. Image data obtained by the Ozone Monitoring Instrument on NASA's Aura satellite.