Recent Intensified Winter Coldness in the Mid-High Latitudes of Eurasia and Its Relationship with Daily Extreme Low Temperature Variability

Figure 4

Statistical significance of correlation coefficients between the ECI and the occurrence of station cold days (a) and cold nights (b). Here, we also used the 10th percentile threshold but substituted a stationary climatology for 1973–1992 following Zhang et al. [27]. The values of the colored bars represent the significance of the two-tailed Student’s -test at each station (dot); the positive (negative) sign denotes a positive (negative) correlation.

(a) Cold days

(b) Cold nights