National Aeronautics and Space Administration

Animated maps of modeled ClONO₂ (a and e), HCl (b and f), ClOx (c and g), and ozone (d and h) on the 480-K potential temperature surface on 11 January 2016 (a-d) and 21 March 2016 (e-h). The black contour is the edge of the polar vortex. Read more. [PDF]