10Be in the Akademii Nauk ice core – first results for CE 1590–1950 and implications for future chronology validation.

Abstract

Global variations of the radionuclide 10Be that are almost simultaneous provide a powerful tool to synchronize 10Be records from different locations. We compared the 10Be record of the Akademii Nauk (AN) ice core (Russian Arctic) for the time period CE 1590-1950 to the 10Be records of two well-dated Greenland ice cores (Dye3 and NGRIP). A high correlation (r=0.60) was found between the AN and Dye3 records, which increases up to 0.78 in certain intervals, whereas the correlation to NGRIP was distinctly lower. Sources of deviations may include local fluctuations in the deposition of 10Be due to changes in the precipitation patterns, artefacts due to the core-sampling strategy and a general bias in the age model. In general, the existing age model was validated confirming the AN ice core to be a unique and well-dated source of palaeoclimate parameters for the Russian Arctic. Because of a possible minor bias in the earliest part of the studied ice-core section, the influence of the core-sampling strategy was studied, based on a numerical model that simulates sampling in a discrete and continuous mode with varying sample lengths. Based on the results of the model to sample continuously with individual samples lengths covering a time span of 4-8 years we developed a new sample strategy for the deeper layers.