Simulated European stalagmite record and its relation to a quasi-decadal climate mode
1Alfred Wegener Institute for Polar and Marine Research, Bussestr. 24, 27570 Bremerhaven, Germany
2Heidelberg Academy of Science, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
3Institut für Geowissenschaften, Johannes-Gutenberg-Universität Mainz, Johann-Joachim-Becher-Weg 21, 55128 Mainz, Germany
*now at: Bjerknes Centre for Climate Research, Bergen, Norway
Abstract. A synthetic stalagmite record for the Bunker cave is constructed using a combined climate-stalagmite modeling approach. The power spectrum of the simulated speleothem calcite δ18O record has a pronounced peak at quasi-decadal time scale. Interestingly, mixing processes in the soil and karst above the cave represent a natural low-pass filter of the speleothem climate archive. We identify a quasi-decadal mode characterized by a "tripole pattern" of sea surface temperature affecting stalagmite δ18O values. This pattern, which is well-known in literature as the quasi-decadal mode in the North Atlantic, propagates eastwards and affects western European temperature surrounding the cave. Stalagmite δ18O values at Bunker Cave lag the regional surface temperature (r = 0.4) and soil moisture (r = −0.4) signal by 2–3 yr. Our modelling study suggests that stalagmite records from Bunker Cave are representative for large-scale teleconnections and can be used to obtain information about the North Atlantic and its decadal variability.