Estimation of Natural Variability and Detection of Anthropogenic Signal in Summertime Precipitation over South America
Figure 1
(a) First EOF of interannual DJF rainfall variability calculated over the region (50°S–10°S; 280°E–330°E) (dashed box) for observations. Contour interval: 0.25 mm/day. The map is constructed by linear regression of the precipitation field onto the time series associated with the EOF. (b) Idem (a) for the HadCM3 20th-century run. (c) Correlation between time series associated with the EOF shown in (a) and SST anomalies for observations. Contour interval: 0.1. Correlation values higher (lower) than 0.35 (−0.35) are significant at a 5% level according to a two-tailed Student t-test. (d) Correlation between time series associated with the EOF shown in (b) and SST anomalies for the HadCM3 20th-century run. Contour interval: 0.1. Correlation values higher (lower) than 0.2 (−0.2) are significant at a 5% level according to a two-tailed Student t-test.
