The evolution of Pleistocene climate: A time series approach

Unlocking the mysteries of the ice ages

“…The glacial cycles of the late Pliocene to early Pleistocene (~1-3 million years ago) were more regular than those of the late Pleistocene, typically lasting about 41,000 years ( Fig. 1a), which matches the period of change in Earth's tilt 2 (Fig. 1b).…”

The middle Pleistocene transition: characteristics, mechanisms, and implications for long-term changes in atmospheric pCO2

“…There is wide disagreement in defining when this MPT occurred, with descriptions ranging from an abrupt versus gradual transition that began as early as 1500 ka and as late as 600 ka (e.g., Pisias and Moore, 1981;Prell, 1982;Ruddiman et al, 1989;Park and Maasch, 1993;Mudelsee and Schulz, 1997;Rutherford and D'Hondt, 2000). To a large extent, these differing conclusions can be explained by the analysis of individual d 18 O b records, the details of which may differ due to regional differences in salinity and temperature, masking the global ice-volume and deep-water temperature signal.…”

“…1a). Using time-series analytical methods, Pisias and Moore (1981) confirmed the spectral change seen in V28-239, which has since become generally known as the middle Pleistocene transition (MPT). Moreover, they noted that because variations in the Earth's orbital parameters did not change over the last 2000 ka, ''the nature of the climate response, as well as its time constant to external forcing, may have evolved and changed with time'' (p. 451).…”

On the importance of centennial variability for ice ages

“…Pisias and Moore 1981) remarked that when the power spectrum of climate variations is plotted on a log-log form, the so-called Milankovitch peaks become almost anecdotal. The visual impression is rather that of a noisy process encompassing slow and fast variability.…”