Fig. 1: SSW composites for mean and extreme indices of daily surface temperature.
From: Stratospheric drivers of extreme events at the Earth’s surface
Difference between the composite of the 30 days following 24 observed SSWs and the composite of n randomly sampled 30-day periods from Dec-Apr, repeated 3000 times, for a daily mean surface temperature anomalies, b the coldest (within the 30-day period) daily minimum surface temperature anomaly, and c the warmest (within the 30-day period) daily maximum surface temperature anomaly. Surface temperature data and SSW dates are calculated using ERA-interim reanalysis (1979–2016)131. Stippling shows where the SSW composite anomalies are significantly different (p < 0.05, using a bootstrap with replacement test) from the randomly sampled composite anomalies.
