Simulated European stalagmite record and its relation to a quasi-decadal climate mode

A synthetic stalagmite delta O-18 record for the Bunker Cave (51 degrees N, 7 degrees E) is constructed using a combined climate-stalagmite modelling approach where we combine an atmospheric circulation model equipped with water isotopes and a model simulating stalagmite calcite delta O-18 values. Mixing processes in the soil and karst above the cave represent a natural low-pass filter of the speleothem climate archive. Stalagmite delta O-18 values at Bunker Cave lag the regional surface climate by 3-4 yr. The power spectrum of the simulated speleothem calcite delta O-18 record has a pronounced peak at quasi-decadal time scale, which is associated with a large-scale climate variability pattern in the North Atlantic. 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.