δ 18O analyses to calibrate slow growth rate speleothem records with regional δ 18O records of precipitation]]>

摘要

AbstractPaleoclimate reconstructions based on speleothems require a robust interpretation of their proxies. Detailed transfer functions of external signals to the speleothem can be obtained using models supported by monitoring data. However, the transferred signal may not be stationary due to complexity of karst processes. Therefore, robust interpretations require the calibration of speleothem records with instrumental time series lasting no less than a decade. We present the calibration of a speleothemδ18O record from Postojna Cave (Slovenia) with the regional record ofδ18O composition of precipitation during the last decades. Using local meteorological data and a regionalδ18O record of precipitation, we developed a model that reproduces the cave drip waterδ18O signal measured during a two-year period. The model suggests that the aver