Climate of the Past

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Clim. Past Discuss., 5, 2223-2237, 2009
www.clim-past-discuss.net/5/2223/2009/
doi:10.5194/cpd-5-2223-2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.

Potential analysis reveals changing number of climate states during the last 60 kyr

V. N. Livina1, F. Kwasniok2, and T. M. Lenton1
1School of Environmental Sciences, University of East Anglia, Norwich, UK
2School of Engineering, Computing and Mathematics, University of Exeter, Exeter, UK

Abstract. We develop and apply a new statistical method of potential analysis for detecting the number of states of a geophysical system, from its recorded time series. Estimation of the degree of a polynomial potential allows us to derive the number of potential wells in a system. The method correctly detects changes in the number of wells in artificial data. In ice-core proxy records of Greenland paleotemperature, a reduction in the number of climate states from two to one is detected sometime prior to the last glacial maximum (LGM), 23–19 kyr BP. This bifurcation can be interpreted as loss of stability of the warm interstadial state of the Dansgaard-Oeschger events. In data spanning the last glacial termination, up to four climate states are detected, plausibly representing the LGM, Bolling-Allerod, Younger Dryas, and the Holocene. The proposed method can be applied to a wide range of geophysical time series exhibiting bifurcations.

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Citation: Livina, V. N., Kwasniok, F., and Lenton, T. M.: Potential analysis reveals changing number of climate states during the last 60 kyr, Clim. Past Discuss., 5, 2223-2237, doi:10.5194/cpd-5-2223-2009, 2009.   Bibtex   EndNote   Reference Manager    XML
 

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