stratospheric sudden warming, Arctic ozone, satellite data, Stratosphere, Atmospheric circulation, Winter, Meteorology, Polar vortex, Thresholds, Chlorine, Variability, Stratopause, Temperature gradients, Fluid flow, Trace gases, Ozone, Stratospheric warming, Aerodynamics, Activation, Gases, Sensitivity, Stratospheric temperatures, Temperature effects, Air t...