ALBERT

Description: Vertical profiles of water temperature, pressure and salinity were measured by the Drift Towing Ocean Profiler (DTOP) buoy 2019V4, a.k.a. 2019E, an autonomous platform, installed on drifting sea ice in the Arctic Ocean during MOSAiC (Leg 1) 2019/20. The resulting time series describes the vertical profile of the ocean below the sea ice as a function of place and time between 09 October 2019 and 17 August 2020 in sample intervals of 12 hours. In addition, the DTOP measured air temperature, relative humidity and barometric pressure and GPS position at hourly intervals. This instrument was deployed as part of the projects National Key R&D Program of China and The Marine S&T Fund of Shandong Province for Qingdao National Laboratory for Marine Science and Technology.

Description: We present a continuous and well-resolved record of climatic variability for the past 100,000 yrs from a marine sediment core taken in Delagoa Bight, off southeastern Africa. In addition to providing a sea surface temperature reconstruction for the past ca. 100,000 yrs, this record also allows a high-resolution continental climatic reconstruction. Climate sensitive organic proxies, like the distribution and isotopic composition of plant-wax lipids as well as elemental indicators for fluvial input and weathering type provide information on climatic changes in the adjacent catchment areas (Incomati, Matola, and Lusutfu rivers). At the transition between glacials and interglacials, shifts in vegetation correlate with changes in sea surface temperature in the Agulhas current. The local hydrology, however, does not follow these orbital-paced shifts. Instead, precipitation patterns follow millennial scale variations with different forcing mechanisms in glacial versus interglacial climatic states. During glacials, southward displacement of the Intertropical Convergence Zone facilitates a transmission of northern hemispheric signals (e.g. Heinrich events) to the southern hemispheric subtropics. Furthermore, the southern hemispheric westerlies become a more direct source of precipitation as they shift northward over the study site, especially during Antarctic cold phases. During interglacials, the observed short-term hydrological variability is also a function of Antarctic climate variability, however, it is driven by the indirect influence of the southern hemispheric westerlies and the associated South African high-pressure cell blocking the South Indian Ocean Convergence Zone related precipitation. As a consequence of the interplay of these effects, small scale climatic zones exist. We propose a conceptual model describing latitudinal shifts of these zones along the southeastern African coast as tropical and temperate climate systems shift over glacial and interglacial cycles. The proposed model explains some of the apparent contradictions between several paleoclimate records in the region.

Description: The data comprise sample locations and results of grain size measurements and optically stimulated luminescence dating of sediments from the Orog Nuur Basin (southern Mongolia). Samples were taken in order to gain a comprehensive sedimentological and geochronological overview over late Quaternary sediment cascades and respective archives. Grain size measurements were conducted in Aachen using a Beckmann Coulter Laser Particle Sizer. OSL data were obtained in the Luminescence lab of Cologne University. Samples were classified into 7 sediment archives according to the field description and grain size analysis (fluvial, beach ridge, lacustrine, littoral sand, dune sand, basin silty sands, and mountain silt). The grain size statistics is presented in the .xlsx-table according to this classification. The combination of sedimentological, geomorphologic and geochronological observations led to a late Quaternary landscape reconstruction, including alluvial fan evolution, lake level history and aeolian dynamics in this arid region of the northern Gobi Desert.

Description: We performed laboratory friction experiments on simulated fault gouges, measuring both the velocity- and slip-dependence of friction in velocity-step tests. Here, we evaluate the relative importance of slip- and velocity-dependent friction in laboratory velocity-stepping experiments, and assess the impact of friction slip dependence on natural faults.As an analogue fault gouge, we used a mixture of silt-sized quartz and commercially obtained clay-rich sediment (Grüne Tonerde, Argiletz Laboratories) mixed with deionized water. All tests were conducted at an (effective) normal stress of 2 MPa, with total shear displacements of up to ~16 mm.

Description: We present a multi-proxy dataset of two sediment cores (0.61 and 0.41 m long) from interconnected infilled depositional basins in the Kobbefjord area, southwestern Greenland. We performed analyses of magnetic susceptibility, grain size distribution, X-ray fluorescence (XRF) element composition , total content of carbon, nitrogen and sulfur, biogenic silica (at 0.5-cm resolution), and diatom stratigraphy (at 1 to 5-cm resolution). The sequences provide evidence of sedimentation in former shallow Arctic lakes or ponds in sparsely glacierized catchments.

Description: Surface ablation/accumulation was measured at 55 locations at the 79°N Glacier (Nioghalvfjerdsbraeen Glacier) in northeast Greenland in 2017 and 2018 (see links in "Further details"). Ablation/Accumulation are measured changes in height above ground level of bamboo poles installed in early July 2017 and changes were measured in late July 2017 or/and in July 2018.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2020T76(a.k.a. PRIC_10_04, IRIDIUM number 300234068528490) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 3rd leg of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in April 2020. The buoy was deployed at the site about 2 km from the ship with initial thicknesses of snow and ice of 0.14 and 150 m, respectively, on 4 April 2020. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2 cm. The depths for the sensors are 72 to -406 cm, referring to the initial interface between snow and ice. The last sensor was used to measure the air temperature at 1 m above the initial snow surface. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of depth and time between 4 April 2020 and 20 July 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, tilt and compass were measured.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2020T77 (a.k.a. PRIC_10_05, IRIDIUM number 300234068524740) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 3rd leg of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in April 2020. The buoy was deployed at the site about 2 km from the ship with initial thicknesses of snow and ice of 0.06 and 1.64 m, respectively, on 4 April 2020. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2 cm. The depths for the sensors are 84 to -394 cm, referring to the initial interface between snow and ice. The last sensor was used to measure the air temperature at 1 m above the initial snow surface. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of depth and time between 4 April 2020 and 4 June 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, tilt and compass were measured.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2020T75 (a.k.a. PRIC_10_03, IRIDIUM number 300234068325170) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 3rd leg of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in April 2020. The buoy was deployed at the old helicopter site of central observatorysite with initial thicknesses of snow and ice of 0.12 and 1.64 m, respectively, on 23 April 2020. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2 cm. The depths for the sensors are 56 to -422cm, referring to the initial interface between snow and ice. The last sensor was used to measure the air temperature at 1 m above the initial snow surface. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of depth and time between 23 April 2020 and 6 August 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, tilt and compass were measured.