j@1040: Basics: Proxies |APSC| and |VPSC|
j@1040: ===================================
j@1040: 
j@1040: |APSC| specifies the area at a certain height, which is below a
j@1040: typical temperature threshold below which the chlorine-catalyzed polar
j@1040: ozone depletion takes place.  |VPSC| is the corresponding volume in a
j@1040: given height range (here: 14-22 km).  Here the average value of this
j@1040: size between mid December and the end of March is considered.  Since
j@1040: usually in cold arctic winters there is a stable polar vortex, it has
j@1040: been found empirically that this quantity can provide good
j@1060: approximations for ozone depletion [#]_.  High values of |VPSC| mean
j@1040: high ozone losses.
j@1040: 
j@1040: 
j@1040: .. |APSC| replace:: A\ :sub:`PSC`\ 
j@1040: .. |VPSC| replace:: V\ :sub:`PSC`\ 
j@1040: .. |H2O| replace:: H\ :sub:`2`\ O
j@1040: .. [#] see e.g. Rex, M. et al., Geophys. Res. Lett., 31, doi:10.1029/2003GL018844, 2004
j@1040: