Figure 2.28: Reconstructions
since 1700 of proxy-based ENSO indices. Shown are the Northern Hemisphere cold-season
(Oct-Mar) mean NINO 3 index of Mann et al. (2000a) and the Northern Hemisphere
winter SOI index of Stahle et al. (1998). The SOI series is scaled to have the
same standard deviation as the NINO 3 index, and is reversed in sign to be positively
correlated with the NINO 3 series. An instrumental NINO 3 index from 1871 to 2000
is shown for comparison (Rayner et al., 2000; see also Figure 2.29), with two
standard error limits (grey shaded) of the proxy NINO 3 reconstruction.