Climate Dynamics

, Volume 34, Issue 6, pp 781–795

Unprecedented low twentieth century winter sea ice extent in the Western Nordic Seas since A.D. 1200


    • Biogeoscience InstituteUniversity of Calgary
    • Department of GeologyUniversity of Helsinki
    • Rovaniemi Research StationFinnish Forest Institute
    • Department of Ecology, Faculty of BiologyUniversity of Barcelona
  • A. Grinsted
    • Centre for Ice and Climate, Niels Bohr InstituteUniversity of Copenhagen
    • Arctic CentreUniversity of Lapland
  • S. Helama
    • Department of GeologyUniversity of Helsinki
  • J. Moore
    • Arctic CentreUniversity of Lapland
    • Thule InstituteUniversity of Oulu
    • College of Global Change and Earth System ScienceBeijing Normal University
  • M. Timonen
    • Rovaniemi Research StationFinnish Forest Institute
  • T. Martma
    • Institute of GeologyTallinn University of Technology
  • E. Isaksson
    • Polar Environmental CentreNorwegian Polar Institute
  • M. Eronen
    • Department of GeologyUniversity of Helsinki

DOI: 10.1007/s00382-009-0610-z

Cite this article as:
Macias Fauria, M., Grinsted, A., Helama, S. et al. Clim Dyn (2010) 34: 781. doi:10.1007/s00382-009-0610-z


We reconstructed decadal to centennial variability of maximum sea ice extent in the Western Nordic Seas for A.D. 1200–1997 using a combination of a regional tree-ring chronology from the timberline area in Fennoscandia and δ18O from the Lomonosovfonna ice core in Svalbard. The reconstruction successfully explained 59% of the variance in sea ice extent based on the calibration period 1864–1997. The significance of the reconstruction statistics (reduction of error, coefficient of efficiency) is computed for the first time against a realistic noise background. The twentieth century sustained the lowest sea ice extent values since A.D. 1200: low sea ice extent also occurred before (mid-seventeenth and mid-eighteenth centuries, early fifteenth and late thirteenth centuries), but these periods were in no case as persistent as in the twentieth century. Largest sea ice extent values occurred from the seventeenth to the nineteenth centuries, during the Little Ice Age (LIA), with relatively smaller sea ice-covered area during the sixteenth century. Moderate sea ice extent occurred during thirteenth–fifteenth centuries. Reconstructed sea ice extent variability is dominated by decadal oscillations, frequently associated with decadal components of the North Atlantic Oscillation/Arctic Oscillation (NAO/AO), and multi-decadal lower frequency oscillations operating at ~50–120 year. Sea ice extent and NAO showed a non-stationary relationship during the observational period. The present low sea ice extent is unique over the last 800 years, and results from a decline started in late-nineteenth century after the LIA.


Sea icePaleoclimatologyNordic seasGlobal warmingIce coreDendroclimatologySvalbardFennoscandiaNAOAOLittle Ice Age

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© Springer-Verlag 2009