Can we predict the duration of an interglacial?
| Type | Article | ||||||||
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| Date | 2012 | ||||||||
| Language | English | ||||||||
| Author(s) | Tzedakis P. C.1, Wolff E. W.2, Skinner L. C.3, Brovkin V.4, Hodell D. A.3, McManus J. F.5, Raynaud D.6 | ||||||||
| Affiliation(s) | 1 : UCL, Dept Geog, Environm Change Res Ctr, London WC1E 6BT, England. 2 : British Antarctic Survey, Cambridge CB3 0ET, England. 3 : Univ Cambridge, Dept Earth Sci, Cambridge CB2 3EQ, England. 4 : Max Planck Inst Meteorol, D-20146 Hamburg, Germany. 5 : Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. 6 : Univ Grenoble 1, CNRS, Lab Glaciol & Geophys Environm, F-38402 St Martin Dheres, France. |
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| Source | Climate Of The Past (1814-9324) (Copernicus Gesellschaft Mbh), 2012 , Vol. 8 , N. 5 , P. 1473-1485 | ||||||||
| DOI | 10.5194/cp-8-1473-2012 | ||||||||
| WOS© Times Cited | 64 | ||||||||
| Abstract | Differences in the duration of interglacials have long been apparent in palaeoclimate records of the Late and Middle Pleistocene. However, a systematic evaluation of such differences has been hampered by the lack of a metric that can be applied consistently through time and by difficulties in separating the local from the global component in various proxies. This, in turn, means that a theoretical framework with predictive power for interglacial duration has remained elusive. Here we propose that the interval between the terminal oscillation of the bipolar seesaw and three thousand years (kyr) before its first major reactivation provides an estimate that approximates the length of the sea-level high-stand, a measure of interglacial duration. We apply this concept to interglacials of the last 800 kyr by using a recently-constructed record of interhemispheric variability. The onset of interglacials occurs within 2 kyr of the boreal summer insolation maximum/precession minimum and is consistent with the canonical view of Milankovitch forcing pacing the broad timing of interglacials. Glacial inception always takes place when obliquity is decreasing and never after the obliquity minimum. The phasing of precession and obliquity appears to influence the persistence of interglacial conditions over one or two insolation peaks, leading to shorter (similar to 13 kyr) and longer (similar to 28 kyr) interglacials. Glacial inception occurs approximately 10 kyr after peak interglacial conditions in temperature and CO2, representing a characteristic timescale of interglacial decline. Second-order differences in duration may be a function of stochasticity in the climate system, or small variations in background climate state and the magnitude of feedbacks and mechanisms contributing to glacial inception, and as such, difficult to predict. On the other hand, the broad duration of an interglacial may be determined by the phasing of astronomical parameters and the history of insolation, rather than the instantaneous forcing strength at inception. | ||||||||
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