Figure 8.

The effect of data aggregation on early warning of thermohaline circulation collapse in a coupled ocean–atmosphere model. Based on aggregating results from the GENIE-2 model (figure 7a). Contour plots show the value of the Kendall trend statistic for the ACF indicator derived after detrending by Gaussian filtering, when varying the sliding window length and filtering bandwidth. Analysis based on (a) raw data (as in figure 7c), (b) data averaged to Δt=5 years (n=1054), (c) Δt=10 years (n=527) or (d) Δt=20 years (n=263) resolution. Note the change in bandwidth range between (a) and (b–d).