Correction to "Mode shift in the Indian Ocean climate under global warming stress"

In the paper Mode shift in the Indian Ocean climate under global warming stress by Nobuko Nakamura et al. (Geophysical Research Letters, 36, L23708, doi:10.1029/2009GL040590, 2009), coral IOD index was evaluated by determining its correlation coefficient with the observational data with r2; however, we made a simple mistake, and r2 should be r in the text and figures. We corrected this mistake in page 2 line 3 (right side), page 4 line 15 (right side) and Figure S6 in the auxiliary material of Nakamura et al. [2009]. We also corrected the same mistake in page 4 lines 16, 18 and 20 (left side) of Kayanne et al. [2006], the first report of this coral IOD series. Nakamura et al. reconstructed 115-year IOD variability related to East African Short Rain variability based on the coral IOD index derived from the Kenyan coral monthly 18O record. Our coral IOD index is defined as the coral 18O values assigned to January of the following year, which reflects the Short Rain anomalies for the previous September to November. At this time, we would like to re-evaluate and reconfirm the validity of the coral IOD index by determining the confidence interval and its determining factors. The correlation coefficient (r) between the Mombasa rainfall (SON) anomaly and coral IOD index for 19861999 is 0.77 (Table 1), and the standard error for this estimation is 0.10. Figure 1 shows the scatter plots correlating the Mombasa rainfall (SON) anomaly with the coral IOD index for the last 40 years. The coefficient of determination between the Mombasa rainfall (SON) anomaly and coral IOD index for 19591999 is low (solid line in Figure 1: r2 = 0.33); however, it increases to r2 = 0.69 in the IOD years (red crosses and dashed line in Figure 1). This observation indicates that the coral index accurately separates East African Short Rain anomalies related to IOD and validates the reconstruction of past IOD variability using this coral index. [Figure omitted, see PDF] Figure 1. Scatter plot correlating the Mombasa rainfall (SON) anomaly with the coral IOD index for 19591999. The brown diamonds and red cross marks represent plots corresponding to the coral IOD index and positive/negative IOD years from DMI, respectively. IOD years are based on Table 1 in Yamagata et al. [2004]. The brown solid and red dashed lines represent the regression line between the Mombasa raincoral index and Mombasa raincoral index in IOD years. The factor affecting the moderate correlation between the coral IOD ind