Extended Data Fig. 9: Relationship between projected changes in ENSO and in pIOD.
From: Opposite response of strong and moderate positive Indian Ocean Dipole to global warming
a, Scatter plot of changes in September, October, and November (SON) S-index variability versus changes in SON Ni\({\tilde{\mathrm n}}\)o3.4 index variability. The change is defined as the difference between the present-day (1900–1999) and future (2000–2099) period scaled by the corresponding increase in global mean SST in each model. b, Same as a, but between changes in SON M-index variability and in SON Ni\({\tilde{\mathrm n}}\)o3.4 index variability. c, d, Same as a, b, but for changes in strong pIOD (S-index>1.5 s.d.) or moderate pIOD (M-index>1.25 s.d.) frequency (events per 100 years) vs frequency of El Ni\({\tilde{\mathrm n}}\)o (Ni\({\tilde{\mathrm n}}\)o3.4>1.0 s.d.). The associated correlation coefficient and P-value are plotted. There is no relationship between changes in El Niño and S-index in a and c. Although there is a positive correlation in b and d, the changes in M-index and in El Niño are in the opposite direction, contravening the relationship between El Ni\({\tilde{\mathrm n}}\)o and M-index.
