Estimates of Arctic ozone loss from temperature

 ===============================================

 Here you can see the temporal development of the area with

 temperatures below a typical threshold temperature that is needed for

 for chlorine-catalyzing polar ozone depletion.  The mean value of the

 volume of these low temperatures is a measure of the Ozone depletion.

 The upper panel shows the temporal development of the area with temperatures

 below this temperature threshold. The lower panel shows the corresponding

 volume (solid line) and the mean value between mid-December and 

 End of March (dotted line and right arrow). 

 For comparison, the corresponding mean values of other years are shown as coloured 

 arrows displayed at the right edge of the plot. In 2011 this quantity was

 about :math:`38 \cdot 10^6` km :math:`^3`.