Climate and ice conditions of East Siberian Sea during Holocene: Reconstructions based on sedimentary geochemical multiproxy
А. С. Астахов, Valeriy V. Babich, Xuefa Shi, Limin Hu, M. S. Obrezkova, К. И. Аксентов, A.V. Alatortsev, A. V. Darin, И. А. Калугин, В. Н. Карнаух, M. S. Melgunov
Abstract
Reconstruction of ice conditions and climate of the East Siberian Sea during the Late Middle Holocene was implemented for the first time using a transfer function method based on marine sedimentation proxies. Transfer functions were developed based on a hydrometeorological time series of changes in mean annual air temperature (ΔT 10 ) and the ice-free period (IF 10 ) for the last 70–90 years and a geochemical time series of bottom sediments accumulated during this time, which were obtained using a submillimeter scanning of the core in the X-ray fluorescence analysis of synchrotron radiation. Geochemical time series of Holocene deposits were obtained from X-ray fluorescence analysis of the core in a step of 1–2 cm. Reconstruction of ice conditions and average annual air temperature revealed a decreasing trend of ΔT 10 and IF 10 , which started from the middle Holocene up to the Little Ice Age due to an orbitally determined decrease in insolation. A synchronous periodicity of changes in ice cover and air temperature was revealed and approximated by periods of 1600 years for IF10 and 1740 years for ΔT 10 , which are comparable to Bond’s climatic cycles. These results indicates the telecommunication of the Atlantic processes, climate of the East Siberian Sea, and predominance of the cyclonic type of atmospheric circulation during the Holocene.