2 Development of ozone depletion over the years
3 =============================================
5 Chemical ozone depletion is not a quantity that can be measured
6 directly. Ozone is also influenced by atmospheric transport. The time
7 at which the polar vortex breaks down varies from year to year. One
8 way to deduce the effect of chemical ozone depletion from the
9 measurements is tto look at of the average ozone column in the polar
10 vortex ("equivalent latitude" >63°). This quantity increases
11 after the breakdown of the polar vortex (typically in March) due to
12 the the transport of ozone-rich air masses towards the pole.
13 Therefore the minimum of this quantity in March is an approximate measure
14 of chemical ozone depletion in the Arctic. Here you can see this
15 value for years up to and including 2019 and also the corresponding
16 time series for Antarctica.