(a) Forcing record of the inverse routine, the LR04 benthic δ18O stacked record16. (b) Wavelet analysis48 of LR04. (c) Simulated surface-air temperature anomaly (°C) over Antarctica and (d) wavelet analysis of temperature. (e) Simulated Antarctic ice volume (106 km3) and (f) wavelet analysis of ice volume. (g) Eastern equatorial Pacific Leg 138 benthic δ13C record13 and (h) wavelet analysis of δ13C. For b,d,f,h, the >95% confidence levels are indicated by the black lines, and horizontal dashed lines indicate the 41, 100 and 400 kyr frequencies. The light shading indicates possible distorted results due to edge effects of the time series. On the left, the total power spectrum with the 95% confidence level indicated by the dashed line.