Extended Data Fig. 6: Trends in AMOC, fingerprint indices and E−P.
From: Weakening Atlantic overturning circulation causes South Atlantic salinity pile-up
a–d, Cross-model scatter plots between the trends of the fingerprint indices and AMOC transport in the historical run (1861–2018, circles, with the period 2006–2018 using the RCP8.5 scenario) and for the future period 2019–2100 in RCP4.5 (triangle) and RCP8.5 (square) scenarios with the cross-ensemble correlations R shown in the lower left corners of the panels. a, AMOC versus SN (R = 0.64). b, AMOC versus TNA (R = 0.75). c, (E−P)S versus SS (R = −0.03). d, (E−P)N versus SN (R = 0.62, for comparison with ‘S’ in c, here ‘N’ represents the difference of North Atlantic with North Pacific). Panel c shows no correlation between the trends of local (E−P)S and SS, in contrast to the AMOC (Fig. 3c), suggesting the AMOC as the dominant driving force. By contrast, d shows that E−P is a strong forcing of salinity pile-up in North Atlantic, comparable with AMOC (a). The R value is calculated without the CanESM2 model (grey), which appears to be an outlier model for the trends of AMOC and all the indices, with the P > 0.1 significance level as R = 0.22 (against a white noise with sample size n = 36, one-tailed test).
