Fig. 3: The SMOPI definition and links with the leading mode of the Sahel rainfall variability.
From: The global Sahel monsoon ocean-pressure index reconciles its regional and large-scale features
a 5-year smoothed of the temporal evolutions of the SMOPI intensity over the period 1965-2014, from JRA55 (blue), ERA5 (green), MPI-ESM1-2-LR (purple) and CMIP6 (red). The results from the 29 CMIP6 models are also shown (thin red curves). Shaded bands represent the mean ±1 standard deviation for each dataset, except for CMIP6, where the band indicates the inter-model spread. Half-regression lines are shown for the two main rainfall sequences of the Sahel study period: the drying phase (1965-1985) and the rainfall recovery phase (1986-2014). b The SMOPI intensity (solid lines) and PC1 rainfall anomalies (dashed lines) are superimposed, along with their respective uncertainty ranges. r-values represent the correlation between the SMOPI intensity and PC1 rainfall anomalies. The asterisk (*) marks statistical significance (p < 0.01) based on a two-sided Student’s t-test. Spatial distribution of correlation coefficients (c) and regression slope (d) between the SMOPI intensity and the Sahel PC1 rainfall anomalies at subseasonal time scale, from JRA55, ERA5, MPI-ESM1-2-LR and CMIP6. Only statistically significant values (p < 0.01) are shown.
