Figure 2

Thirty-five year regional average values and trend magnitudes of monthly SMN, SMT, precipitation and their correlations for the period of 1982–2016 in Jing-Jin-Ji region. (a) SMN; (b) SMT; (c) precipitation; and (d) Correlation coefficients between SMN and SMT/precipitation. The empty circles indicate statistically significant trends at 5% significance level, and the dash lines indicate that the SNM is significantly correlated with SMT or precipitation at 5% significance level.