Northern Hemisphere, stratospheric ozone depletion

Profile shapes of upper stratospheric ozone depletion and C10/Cly Satellite and ground-based Northern Hemisphere mid-latitude 30-50 Gas-phase chlorine chemistry, particularly partitioning processes... 

CFCs released to the atmosphere evenmally find their way up to the stratosphere where they destroy the ozone layer which protects the Earth s surface from harmful ultra-violet radiation. During the last decades, the ozone layer has been severely depleted, both over the Antarctic region where the ozone hole now appears annually, but also over the northern hemisphere. Ozone depletion up to 40% has been recorded in each of the last three years over Northern Europe. 

In more recent times, there have been discoveries of ozone depletion in the Arctic that occur by similar mechanisms as the ones described here (see Figure 28). The Arctic equivalent does not tend to be as dramatic owing to the fact the Artie stratosphere does not get as cold as the Antarctic, mainly owing to a less well-formed vortex, largely owing to northern hemisphere topography. 

In the Southern Hemisphere, chlorine activation leads to a remarkable springtime decrease in ozone that has come to be known as the Antarctic ozone hole on the other hand, polar ozone depletion is considerably smaller in the Arctic. The difference arises from the weaker wave driving of the stratospheric circulation of the Southern Hemisphere. As seen in Fig. 9, wave amplitudes are smaller in the the Southern Hemisphere, and so is wave driving, to the point that the southern polar jet persists much longer into the spring than its northern counterpart. The delayed breakdown of the southern polar vortex allows ozone loss to continue throughout the months of September and October. In the Northern Hemisphere, on the other hand, the conditions necessary for ozone loss usually disappear in mid- to late March, when the northern polar vortex breaks down. 

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