545463.fig.004a
(a)
545463.fig.004b
(b)
Figure 4: OND cyclone track frequency composite for (a) IOD positive relative to negative for NCEP1_5801 (shaded). 2-tailed 90% significance (hatched), (b) like (a) but for ERA40_5801 Units: number of storms per winter for a 5° × 5° box.