Consistent with past studies (e.g., Su and Neelin 2003; Gu et al. 2007), tropical mean
(land+ocean) precipitation has no significant correlation with Nino 3.4 (solid line in Fig. 5a). The
correlation between global mean (land+ocean) precipitation and Nino 3.4 becomes stronger
(dashed line in Fig. 5a), with its peak appearing as Nino 3.4 leads by seven months, despite
barely reaching the 5% significance level. This slightly stronger global correlation may result
from the ENSO modulations of midlatitude storm tracks and associated precipitation (e.g.,
Seager et al. 2005), but certainly warrants further exploration. Tropical mean surface temperature
(SST over ocean and air temperature over land) shows a strong, positive correlation with Nino
3.4, and the peak correlation appears as Nino 3.4 leads by three months (solid line in Fig. 5b).
The correlation between global mean surface temperature and Nino 3.4 is weaker (dashed line in
Fig. 5b),