Can we predict the duration of an interglacial?

Tzedakis, P. C. and Wolff, E. W. and Skinner, L. C. and Brovkin, V. and Hodell, D. A. and McManus, J. F. and Raynaud, D. (2012) Can we predict the duration of an interglacial? Climate of the past, 8 (5). pp. 1473-1485. ISSN 1814-9340 DOI https://doi.org/10.5194/cp-8-1473-2012

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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 highstand, 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 (~ 13 kyr) and longer (~ 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.

Item Type:	Article
Additional Information:	Related url is to discussion
Uncontrolled Keywords:	2012AREP; IA64;
Subjects:	01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions:	01 - Climate Change and Earth-Ocean Atmosphere Systems
Journal or Publication Title:	Climate of the past
Volume:	8
Page Range:	pp. 1473-1485
Identification Number:	https://doi.org/10.5194/cp-8-1473-2012
Depositing User:	Sarah Humbert
Date Deposited:	21 Dec 2012 13:25
Last Modified:	07 Aug 2013 10:50
URI:	http://eprints.esc.cam.ac.uk/id/eprint/2651

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