An automated approach for annual layer counting in ice coresShow others and affiliations
Responsible organisation
2012 (English)In: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 8Article in journal (Refereed) Published
Abstract [en]
A novel method for automated annual layer counting in seasonally-resolved paleoclimate records has been developed. It relies on algorithms from the statistical framework of hidden Markov models (HMMs), which originally was developed for use in machine speech recognition. The strength of the layer detection algorithm lies in the way it is able to imitate the manual procedures for annual layer counting, while being based on statistical criteria for annual layer identification. The most likely positions of multiple layer boundaries in a section of ice core data are determined simultaneously, and a probabilistic uncertainty estimate of the resulting layer count is provided, ensuring an objective treatment of ambiguous layers in the data. Furthermore, multiple data series can be incorporated and used simultaneously. In this study, the automated layer counting algorithm has been applied to two ice core records from Greenland: one displaying a distinct annual signal and one which is more challenging. The algorithm shows high skill in reproducing the results from manual layer counts, and the resulting timescale compares well to absolute-dated volcanic marker horizons where these exist.
Place, publisher, year, edition, pages
2012. Vol. 8
Keywords [en]
hidden markov-models greenland ice probabilistic functions speech recognition chronology signals project records chains event Geology Meteorology & Atmospheric Sciences
Research subject
SWEDARP 1997/98, EPICA 1997/98; SWEDARP 2001/02, EPICA 2001/02; SWEDARP 2002/03, EPICA 2002/03; SWEDARP 2003/04, EPICA 2003/04; SWEDARP 2004/05, EPICA 2004/05; SWEDARP 2005/06, EPICA 2005/06
Identifiers
URN: urn:nbn:se:polar:diva-1944DOI: 10.5194/cp-8-1881-2012OAI: oai:DiVA.org:polar-1944DiVA, id: diva2:810196
Note
ISI Document Delivery No.: 058XP Times Cited: 4 Cited Reference Count: 36 Winstrup, M. Svensson, A. M. Rasmussen, S. O. Winther, O. Steig, E. J. Axelrod, A. E. Svensson, Anders/A-2643-2010; Rasmussen, Sune/B-5560-2008; Winstrup, Mai/M-5844-2014 Svensson, Anders/0000-0002-4364-6085; Rasmussen, Sune/0000-0002-4177-3611; Winstrup, Mai/0000-0002-4794-4004 Danish National Research Foundation under Centre for Ice and Climate at the University of Copenhagen; Inge Lehmann Fonden; Denmark (SNF); Belgium (FNRS-CFB); France (IFRTP); France (INSU/CNRS); Germany (AWI); Iceland (RannIs); Japan (MEXT); Sweden (SPRS); Switzerland (SNF); United States of America (NSF); Carlsberg Foundation This work was supported by the Danish National Research Foundation under Centre for Ice and Climate at the University of Copenhagen. The authors would also like to thank Inge Lehmann Fonden that contributed with financial support. The work is a contribution to the NorthGRIP ice core project, which is directed and organised by the Department of Geophysics at the Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen. It is being supported by funding agencies in Denmark (SNF), Belgium (FNRS-CFB), France (IFRTP and INSU/CNRS), Germany (AWI), Iceland (RannIs), Japan (MEXT), Sweden (SPRS), Switzerland (SNF) and the United States of America (NSF). The work is also a contribution to the Copenhagen Ice Core Dating Initiative that is supported by a grant from the Carlsberg Foundation. 4 Copernicus gesellschaft mbh Gottingen Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences
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