The nature of MIS 3 stadial-interstadial transitions in Europe: New insights from model-data comparisons
2011 (English)In: Quaternary Science Reviews, ISSN 0277-3791, Vol. 30, no 25-26, 3618-3637 p.Article in journal (Refereed) Published
15 abrupt warming transitions perturbed glacial climate in Greenland during Marine Isotope Stage 3 (MIS 3, 60-27 ka BP). One hypothesis states that the 8-16 degrees C warming between Greenland Stadials (GS) and Interstadials (GI) was caused by enhanced heat transport to the North Atlantic region after a resumption of the Atlantic Meridional Overturning Circulation (AMOC) from a weak or shutdown stadial mode. This hypothesis also predicts warming over Europe, a prediction poorly constrained by data due to the paucity of well-dated quantitative temperature records. We therefore use a new evidence from biotic proxies and a climate model simulation to study the characteristics of a GS-GI transition in continental Europe and the link to enhanced AMOC strength. We compare reconstructed climatic and vegetation changes between a stadial and subsequent interstadial - correlated to GS15 and GI14 (similar to 55 ka BP) - with a simulated AMOC resumption using a three-dimensional earth system model setup with early-MIS 3 boundary conditions. Over western Europe (12 degrees W-15 degrees E), we simulate twice the annual precipitation, a 17 degrees C warmer coldest month, a 8 degrees C warmer warmest month, 1300 degrees C-day more growing degree days with baseline 5 degrees C (GDD5) and potential vegetation allowing tree cover after the transition. However, the combined effect of frequent killing frosts, <20 mm summer precipitation and too few GDD5 after the transition suggest a northern tree limit lying at similar to 50 degrees N during GI14. With these 3 climatic limiting factors we provide a possible explanation for the absence of forests north of 48 degrees N during MIS 3 interstadials with mild summers. Finally, apart from a large model bias in warmest month surface air temperatures, our simulation is in reasonable agreement with reconstructed climatic and vegetation changes in Europe, thus further supporting the hypothesis.
Place, publisher, year, edition, pages
2011. Vol. 30, no 25-26, 3618-3637 p.
Abrupt climate change, Last glacial period, Marine Isotope Stage 3, Palaeoclimate modelling
IdentifiersURN: urn:nbn:se:su:diva-71158DOI: 10.1016/j.quascirev.2011.08.002ISI: 000298204000006OAI: oai:DiVA.org:su-71158DiVA: diva2:483887
authorCount :112012-01-262012-01-262012-01-26Bibliographically approved