Standardized diatom data of sediment core PG2023 from Lake Kyutyunda (Yakutia, Russia)

This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized diatom count data of sediment core PG2023, retrieved in 2010 from Lake Ozero Kyutyunda (Yakutia, Russia) at 2.9 m water depth. The thermokarst lake Ozero Kyutyunda is isituated in the coniferous forest area and has one outflow, one inflow and several smaller inflows. It lies at an elevation of ca. 56 m a.s.l. with a surface area of ca. 4.9 km2 and a maximum lake water depth of estimated 3.5 m. The 7.1 m sediment core was retrieved by a UWITEC 60mm piston corer during the RU-Land_2010_Lena expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). Diatoms have been counted using a Zeiss AXIO Scope.A1 light microscope with a Plan-Apochromat 100/1.4 Oil Ph3 objective at 1000x magnification

Standardized mineral data of sediment core PG2023 from Lake Kyutyunda (Yakutia, Russia)

This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized mineral data of sediment core PG2023, retrieved in 2010 from Lake Ozero Kyutyunda (Yakutia, Russia) at 2.9 m water depth. The thermokarst lake Ozero Kyutyunda is situated in the coniferous forest area and has one outflow, one inflow and several smaller inflows. It lies at an elevation of ca. 56 m a.s.l. with a surface area of ca. 4.9 km2 and a maximum lake water depth of estimated 3.5 m. The 7.1 m sediment core was retrieved by a UWITEC piston corer during the RU-Land_2010_Lena expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). Bulk mineralogy was analysed by x-ray diffractometry (XRD) using a (PHILIPS, Netherlands) PW1820 goniometer

Standardized element data of sediment core PG2023 from Lake Kyutyunda (Yakutia, Russia)

This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized X-ray fluorescence line scanning (XRF)-based element data of sediment core PG2023, retrieved in 2010 from Lake Ozero Kyutyunda (Yakutia, Russia) at 2.9 m water depth. The thermokarst lake Ozero Kyutyunda is in an exorheic basin in the coniferous forest area and has one outflow, one inflow and several smaller inflows. It lies at an elevation of ca. 56 m a.s.l. with a surface area of ca. 4.9 km2 and a maximum lake water depth of estimated 3.5 m. The 7.1 m sediment core was retrieved by a UWITEC 60mm piston corer during the RU-Land_2010_Lena expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). The downcore elemental composition was measured using an AVAATECH x-ray fluorescence core scanner at AWI Bremerhaven

Profiles of diatoms, pollen, XRD, XRF and organic composition of two sediment cores (PG2022 and PG2023) from Lake Kyutyunda in Yakutia, NE Siberia, Russia

Although the climate development over the Holocene in the Northern Hemisphere is well known, palaeolimnological climate reconstructions reveal spatiotemporal variability in northern Eurasia. Here we present a multi-proxy study from north-eastern Siberia combining sediment geochemistry, and diatom and pollen data from lake-sediment cores covering the last 38,000 cal. years. Our results show major changes in pyrite content and fragilarioid diatom species distributions, indicating prolonged seasonal lake-ice cover between ~13,500 and ~8,900 cal. years BP and possibly during the 8,200 cal. years BP cold event. A pollen-based climate reconstruction generated a mean July temperature of 17.8°C during the Holocene Thermal Maximum (HTM) between ~8,900 and ~4,500 cal. years BP. Naviculoid diatoms appear in the late Holocene indicating a shortening of the seasonal ice cover that continues today. Our results reveal a strong correlation between the applied terrestrial and aquatic indicators and natural seasonal climate dynamics in the Holocene. Planktonic diatoms show a strong response to changes in the lake ecosystem due to recent climate warming in the Anthropocene. We assess other palaeolimnological studies to infer the spatiotemporal pattern of the HTM and affirm that the timing of its onset, a difference of up to 3,000 years from north to south, can be well explained by climatic teleconnections. The westerlies brought cold air to this part of Siberia until the Laurentide ice-sheet vanished 7,000 years ago. The apparent delayed ending of the HTM in the central Siberian record can be ascribed to the exceedance of ecological thresholds trailing behind increases in winter temperatures and decreases in contrast in insolation between seasons during the mid to late Holocene as well as lacking differentiation between summer and winter trends in paleolimnological reconstructions