The journey through the stratosphere takes several years, and, at altitudes above about 25 km, brings the CFC molecules into the glare of hard solar ultraviolet. The photons are energetic enough to break the tight chemical bonds that give the CFCs their stability and non-toxicity at sea level. The broken molecular fragments are very reactive and enter a complicated chain of chemical events. It is they and their reaction products that bring about the destruction of ozone - most conspicuously under the extreme conditions of the Antarctic polar stratosphere, but also, to a lesser extent, in many other places including the Arctic. Our understanding of the stratospheric pumping action, plus the latest observational data, has led to what I think will be a breakthrough in solar physics.
Coriolis effects are once again important.
The Sun's turbulent convection zone, shown orange in the figure, pumps a circulation in the underlying 'tachocline', shown green with its thickness exaggerated for graphical clarity. This has far-reaching consequences for understanding solar spindown history and possible internal variability, and promises to solve a longstanding puzzle about the destruction not of CFCs but of lithium. It should yield otherwise unobtainable information about the Sun's deepest interior, adding value to the observational data. Schematic slice through the Sun. If nothing else were happening then the tachocline would be too deep, today, for consistency with the data.